diff --git a/change/react-native-windows-2020-04-10-13-52-12-SimplifyReactMacros.json b/change/react-native-windows-2020-04-10-13-52-12-SimplifyReactMacros.json
new file mode 100644
index 00000000000..e56d9ac3678
--- /dev/null
+++ b/change/react-native-windows-2020-04-10-13-52-12-SimplifyReactMacros.json
@@ -0,0 +1,8 @@
+{
+  "type": "prerelease",
+  "comment": "Simplified C++ macros and improved their comments",
+  "packageName": "react-native-windows",
+  "email": "vmorozov@microsoft.com",
+  "dependentChangeType": "patch",
+  "date": "2020-04-10T20:52:12.369Z"
+}
\ No newline at end of file
diff --git a/vnext/Microsoft.ReactNative.Cxx.UnitTests/NoAttributeNativeModuleTest.cpp b/vnext/Microsoft.ReactNative.Cxx.UnitTests/NoAttributeNativeModuleTest.cpp
index 45eaa2ecd48..149e39eec87 100644
--- a/vnext/Microsoft.ReactNative.Cxx.UnitTests/NoAttributeNativeModuleTest.cpp
+++ b/vnext/Microsoft.ReactNative.Cxx.UnitTests/NoAttributeNativeModuleTest.cpp
@@ -573,24 +573,24 @@ void RegisterModule(ReactModuleBuilder<SimpleNativeModule2> &moduleBuilder) noex
   moduleBuilder.RegisterSyncMethod(&SimpleNativeModule2::StaticAddSync, L"StaticAddSync");
   moduleBuilder.RegisterSyncMethod(&SimpleNativeModule2::StaticNegateSync, L"StaticNegateSync");
   moduleBuilder.RegisterSyncMethod(&SimpleNativeModule2::StaticSayHelloSync, L"StaticSayHelloSync");
-  moduleBuilder.RegisterConstant(&SimpleNativeModule2::Constant1, L"Constant1");
-  moduleBuilder.RegisterConstant(&SimpleNativeModule2::Constant2, L"const2");
-  moduleBuilder.RegisterConstant(&SimpleNativeModule2::Constant3, L"const3");
-  moduleBuilder.RegisterConstant(&SimpleNativeModule2::Constant4, L"Constant4");
-  moduleBuilder.RegisterConstMethod(&SimpleNativeModule2::Constant5, L"Constant5");
-  moduleBuilder.RegisterConstMethod(&SimpleNativeModule2::Constant6, L"Constant6");
-  moduleBuilder.RegisterEvent(&SimpleNativeModule2::OnIntEvent, L"OnIntEvent");
-  moduleBuilder.RegisterEvent(&SimpleNativeModule2::OnNoArgEvent, L"OnNoArgEvent");
-  moduleBuilder.RegisterEvent(&SimpleNativeModule2::OnTwoArgsEvent, L"OnTwoArgsEvent");
-  moduleBuilder.RegisterEvent(&SimpleNativeModule2::OnPointEvent, L"onPointEvent");
-  moduleBuilder.RegisterEvent(&SimpleNativeModule2::OnStringEvent, L"onStringEvent", L"MyEventEmitter");
-  moduleBuilder.RegisterEvent(&SimpleNativeModule2::OnJSValueEvent, L"OnJSValueEvent");
-  moduleBuilder.RegisterFunction(&SimpleNativeModule2::JSIntFunction, L"JSIntFunction");
-  moduleBuilder.RegisterFunction(&SimpleNativeModule2::JSPointFunction, L"pointFunc");
-  moduleBuilder.RegisterFunction(&SimpleNativeModule2::JSLineFunction, L"lineFunc");
-  moduleBuilder.RegisterFunction(&SimpleNativeModule2::JSNoArgFunction, L"JSNoArgFunction");
-  moduleBuilder.RegisterFunction(&SimpleNativeModule2::JSStringFunction, L"stringFunc", L"MyModule");
-  moduleBuilder.RegisterFunction(&SimpleNativeModule2::JSValueFunction, L"JSValueFunction");
+  moduleBuilder.RegisterConstantField(&SimpleNativeModule2::Constant1, L"Constant1");
+  moduleBuilder.RegisterConstantField(&SimpleNativeModule2::Constant2, L"const2");
+  moduleBuilder.RegisterConstantField(&SimpleNativeModule2::Constant3, L"const3");
+  moduleBuilder.RegisterConstantField(&SimpleNativeModule2::Constant4, L"Constant4");
+  moduleBuilder.RegisterConstantMethod(&SimpleNativeModule2::Constant5, L"Constant5");
+  moduleBuilder.RegisterConstantMethod(&SimpleNativeModule2::Constant6, L"Constant6");
+  moduleBuilder.RegisterEventField(&SimpleNativeModule2::OnIntEvent, L"OnIntEvent");
+  moduleBuilder.RegisterEventField(&SimpleNativeModule2::OnNoArgEvent, L"OnNoArgEvent");
+  moduleBuilder.RegisterEventField(&SimpleNativeModule2::OnTwoArgsEvent, L"OnTwoArgsEvent");
+  moduleBuilder.RegisterEventField(&SimpleNativeModule2::OnPointEvent, L"onPointEvent");
+  moduleBuilder.RegisterEventField(&SimpleNativeModule2::OnStringEvent, L"onStringEvent", L"MyEventEmitter");
+  moduleBuilder.RegisterEventField(&SimpleNativeModule2::OnJSValueEvent, L"OnJSValueEvent");
+  moduleBuilder.RegisterFunctionField(&SimpleNativeModule2::JSIntFunction, L"JSIntFunction");
+  moduleBuilder.RegisterFunctionField(&SimpleNativeModule2::JSPointFunction, L"pointFunc");
+  moduleBuilder.RegisterFunctionField(&SimpleNativeModule2::JSLineFunction, L"lineFunc");
+  moduleBuilder.RegisterFunctionField(&SimpleNativeModule2::JSNoArgFunction, L"JSNoArgFunction");
+  moduleBuilder.RegisterFunctionField(&SimpleNativeModule2::JSStringFunction, L"stringFunc", L"MyModule");
+  moduleBuilder.RegisterFunctionField(&SimpleNativeModule2::JSValueFunction, L"JSValueFunction");
 }
 
 TEST_CLASS (NoAttributeNativeModuleTest) {
diff --git a/vnext/Microsoft.ReactNative.Cxx/Microsoft.ReactNative.Cxx.vcxitems b/vnext/Microsoft.ReactNative.Cxx/Microsoft.ReactNative.Cxx.vcxitems
index 7ba3d8d6089..58c293cb434 100644
--- a/vnext/Microsoft.ReactNative.Cxx/Microsoft.ReactNative.Cxx.vcxitems
+++ b/vnext/Microsoft.ReactNative.Cxx/Microsoft.ReactNative.Cxx.vcxitems
@@ -21,12 +21,9 @@
     <ClInclude Include="$(MSBuildThisFileDirectory)JSValueTreeWriter.h" />
     <ClInclude Include="$(MSBuildThisFileDirectory)JSValueWriter.h" />
     <ClInclude Include="$(MSBuildThisFileDirectory)JSValueXaml.h" />
-    <ClInclude Include="$(MSBuildThisFileDirectory)ModuleMemberRegistration.h" />
     <ClInclude Include="$(MSBuildThisFileDirectory)ModuleRegistration.h" />
-    <ClInclude Include="$(MSBuildThisFileDirectory)ModuleRegistry.h" />
     <ClInclude Include="$(MSBuildThisFileDirectory)NativeModules.h" />
     <ClInclude Include="$(MSBuildThisFileDirectory)ReactError.h" />
-    <ClInclude Include="$(MSBuildThisFileDirectory)ReactMemberInfo.h" />
     <ClInclude Include="$(MSBuildThisFileDirectory)ReactPromise.h" />
     <ClInclude Include="$(MSBuildThisFileDirectory)StructInfo.h" />
   </ItemGroup>
diff --git a/vnext/Microsoft.ReactNative.Cxx/ModuleMemberRegistration.h b/vnext/Microsoft.ReactNative.Cxx/ModuleMemberRegistration.h
deleted file mode 100644
index 004e717bd67..00000000000
--- a/vnext/Microsoft.ReactNative.Cxx/ModuleMemberRegistration.h
+++ /dev/null
@@ -1,75 +0,0 @@
-// Copyright (c) Microsoft Corporation. All rights reserved.
-// Licensed under the MIT License.
-
-// We implement optional parameter macros based on the StackOverflow discussion:
-// https://stackoverflow.com/questions/3046889/optional-parameters-with-c-macros
-// Please refer to it if you want to understand it works.
-
-#pragma once
-#include "ReactMemberInfo.h"
-
-// Internal implementation details.
-// For each registered member we create a static method that registers it.
-// The member Id is generated as a ReactMemberId<__COUNTER__> type.
-// To invoke the static registration methods, we increment ReactMemberId while static member exists.
-#define INTERNAL_REACT_METHOD_3_ARGS(methodType, method, methodName)                             \
-  template <class TClass, class TRegistry>                                                       \
-  static void RegisterMember(                                                                    \
-      TRegistry &registry, winrt::Microsoft::ReactNative::ReactMemberId<__COUNTER__>) noexcept { \
-    registry.Register##methodType##Method(&TClass::method, methodName);                          \
-  }
-
-#define INTERNAL_REACT_METHOD_2_ARGS(methodType, method) INTERNAL_REACT_METHOD_3_ARGS(methodType, method, L## #method)
-
-#define INTERNAL_REACT_MEMBER_3RD_ARG(arg1, arg2, arg3, ...) arg3
-#define INTERNAL_REACT_MEMBER_4TH_ARG(arg1, arg2, arg3, arg4, ...) arg4
-
-#define INTERNAL_REACT_MEMBER_RECOMPOSER2(argsWithParentheses) INTERNAL_REACT_MEMBER_3RD_ARG argsWithParentheses
-#define INTERNAL_REACT_MEMBER_RECOMPOSER3(argsWithParentheses) INTERNAL_REACT_MEMBER_4TH_ARG argsWithParentheses
-
-#define INTERNAL_REACT_METHOD(...) \
-  INTERNAL_REACT_MEMBER_RECOMPOSER2((__VA_ARGS__, INTERNAL_REACT_METHOD_3_ARGS, INTERNAL_REACT_METHOD_2_ARGS, ))
-
-#define INTERNAL_REACT_CONSTANT_2_ARGS(field, constantName)                                      \
-  template <class TClass, class TRegistry>                                                       \
-  static void RegisterMember(                                                                    \
-      TRegistry &registry, winrt::Microsoft::ReactNative::ReactMemberId<__COUNTER__>) noexcept { \
-    registry.RegisterConstant(&TClass::field, constantName);                                     \
-  }
-
-#define INTERNAL_REACT_CONSTANT_1_ARGS(field) INTERNAL_REACT_CONSTANT_2_ARGS(field, L## #field)
-
-#define INTERNAL_REACT_CONSTANT(...) \
-  INTERNAL_REACT_MEMBER_RECOMPOSER2((__VA_ARGS__, INTERNAL_REACT_CONSTANT_2_ARGS, INTERNAL_REACT_CONSTANT_1_ARGS, ))
-
-#define INTERNAL_REACT_EVENT_3_ARGS(field, eventName, eventEmitterName)                          \
-  template <class TClass, class TRegistry>                                                       \
-  static void RegisterMember(                                                                    \
-      TRegistry &registry, winrt::Microsoft::ReactNative::ReactMemberId<__COUNTER__>) noexcept { \
-    registry.RegisterEvent(&TClass::field, eventName, eventEmitterName);                         \
-  }
-
-#define INTERNAL_REACT_EVENT_2_ARGS(field, eventName) \
-  INTERNAL_REACT_EVENT_3_ARGS(field, eventName, /*defined by REACT_MODULE*/ nullptr)
-
-#define INTERNAL_REACT_EVENT_1_ARGS(field) INTERNAL_REACT_EVENT_2_ARGS(field, L## #field)
-
-#define INTERNAL_REACT_EVENT(...)    \
-  INTERNAL_REACT_MEMBER_RECOMPOSER3( \
-      (__VA_ARGS__, INTERNAL_REACT_EVENT_3_ARGS, INTERNAL_REACT_EVENT_2_ARGS, INTERNAL_REACT_EVENT_1_ARGS, ))
-
-#define INTERNAL_REACT_FUNCTION_3_ARGS(field, functionName, moduleName)                          \
-  template <class TClass, class TRegistry>                                                       \
-  static void RegisterMember(                                                                    \
-      TRegistry &registry, winrt::Microsoft::ReactNative::ReactMemberId<__COUNTER__>) noexcept { \
-    registry.RegisterFunction(&TClass::field, functionName, moduleName);                         \
-  }
-
-#define INTERNAL_REACT_FUNCTION_2_ARGS(field, functionName) \
-  INTERNAL_REACT_FUNCTION_3_ARGS(field, functionName, /*defined by REACT_MODULE*/ nullptr)
-
-#define INTERNAL_REACT_FUNCTION_1_ARGS(field) INTERNAL_REACT_FUNCTION_2_ARGS(field, L## #field)
-
-#define INTERNAL_REACT_FUNCTION(...) \
-  INTERNAL_REACT_MEMBER_RECOMPOSER3( \
-      (__VA_ARGS__, INTERNAL_REACT_FUNCTION_3_ARGS, INTERNAL_REACT_FUNCTION_2_ARGS, INTERNAL_REACT_FUNCTION_1_ARGS, ))
diff --git a/vnext/Microsoft.ReactNative.Cxx/ModuleRegistration.h b/vnext/Microsoft.ReactNative.Cxx/ModuleRegistration.h
index e1d4ab577a5..03916ce88e4 100644
--- a/vnext/Microsoft.ReactNative.Cxx/ModuleRegistration.h
+++ b/vnext/Microsoft.ReactNative.Cxx/ModuleRegistration.h
@@ -4,6 +4,17 @@
 #pragma once
 #include "winrt/Microsoft.ReactNative.h"
 
+// We implement optional parameter macros based on the StackOverflow discussion:
+// https://stackoverflow.com/questions/3046889/optional-parameters-with-c-macros
+// Please refer to it if you want to understand it works.
+#define INTERNAL_REACT_GET_ARG_4(arg1, arg2, arg3, arg4, ...) arg4
+#define INTERNAL_REACT_RECOMPOSER_4(argsWithParentheses) INTERNAL_REACT_GET_ARG_4 argsWithParentheses
+
+//
+// The macros below are internal implementation details for macro defined in nativeModules.h
+//
+
+// Register struct as a ReactNative module.
 #define INTERNAL_REACT_MODULE_3_ARGS(moduleStruct, moduleName, eventEmitterName)                                    \
   struct moduleStruct;                                                                                              \
                                                                                                                     \
@@ -23,7 +34,7 @@
   template struct moduleStruct##_ModuleRegistration<int>;                                                           \
                                                                                                                     \
   template <class TRegistry>                                                                                        \
-  void RegisterModule(TRegistry &registry) noexcept {                                                               \
+  constexpr void RegisterModule(TRegistry &registry) noexcept {                                                     \
     registry.RegisterModule(                                                                                        \
         moduleName, eventEmitterName, winrt::Microsoft::ReactNative::ReactMemberId<__COUNTER__>{});                 \
   }
@@ -31,15 +42,31 @@
 #define INTERNAL_REACT_MODULE_2_ARGS(moduleStruct, moduleName) \
   INTERNAL_REACT_MODULE_3_ARGS(moduleStruct, moduleName, nullptr)
 
-#define INTERNAL_REACT_MODULE_1_ARGS(moduleStruct) INTERNAL_REACT_MODULE_2_ARGS(moduleStruct, L## #moduleStruct)
+#define INTERNAL_REACT_MODULE_1_ARG(moduleStruct) INTERNAL_REACT_MODULE_2_ARGS(moduleStruct, L## #moduleStruct)
+
+#define INTERNAL_REACT_MODULE(...) \
+  INTERNAL_REACT_RECOMPOSER_4(     \
+      (__VA_ARGS__, INTERNAL_REACT_MODULE_3_ARGS, INTERNAL_REACT_MODULE_2_ARGS, INTERNAL_REACT_MODULE_1_ARG, ))
+
+// Register struct member.
+// For each registered member we create a static method that registers it.
+// The member Id is generated as a ReactMemberId<__COUNTER__> type.
+// To invoke the static registration methods, we increment ReactMemberId while static member exists.
+#define INTERNAL_REACT_MEMBER_4_ARGS(memberType, member, memberName, moduleName)                 \
+  template <class TClass, class TRegistry>                                                       \
+  constexpr static void RegisterMember(                                                          \
+      TRegistry &registry, winrt::Microsoft::ReactNative::ReactMemberId<__COUNTER__>) noexcept { \
+    registry.Register##memberType(&TClass::member, memberName, moduleName);                      \
+  }
 
-#define INTERNAL_REACT_MODULE_4TH_ARG(arg1, arg2, arg3, arg4, ...) arg4
+#define INTERNAL_REACT_MEMBER_3_ARGS(memberType, member, memberName) \
+  INTERNAL_REACT_MEMBER_4_ARGS(memberType, member, memberName, nullptr)
 
-#define INTERNAL_REACT_MODULE_RECOMPOSER(argsWithParentheses) INTERNAL_REACT_MODULE_4TH_ARG argsWithParentheses
+#define INTERNAL_REACT_MEMBER_2_ARGS(memberType, member) INTERNAL_REACT_MEMBER_3_ARGS(memberType, member, L## #member)
 
-#define INTERNAL_REACT_MODULE(...)  \
-  INTERNAL_REACT_MODULE_RECOMPOSER( \
-      (__VA_ARGS__, INTERNAL_REACT_MODULE_3_ARGS, INTERNAL_REACT_MODULE_2_ARGS, INTERNAL_REACT_MODULE_1_ARGS, ))
+#define INTERNAL_REACT_MEMBER(...) \
+  INTERNAL_REACT_RECOMPOSER_4(     \
+      (__VA_ARGS__, INTERNAL_REACT_MEMBER_4_ARGS, INTERNAL_REACT_MEMBER_3_ARGS, INTERNAL_REACT_MEMBER_2_ARGS, ))
 
 namespace winrt::Microsoft::ReactNative {
 
diff --git a/vnext/Microsoft.ReactNative.Cxx/ModuleRegistry.h b/vnext/Microsoft.ReactNative.Cxx/ModuleRegistry.h
deleted file mode 100644
index 10a8e3bb95a..00000000000
--- a/vnext/Microsoft.ReactNative.Cxx/ModuleRegistry.h
+++ /dev/null
@@ -1,14 +0,0 @@
-#pragma once
-// Copyright (c) Microsoft Corporation. All rights reserved.
-// Licensed under the MIT License.
-
-#include "ReactMemberInfo.h"
-
-namespace winrt::Microsoft::ReactNative {
-
-struct ModuleRegistry {
-  template <class TClass, int I>
-  void RegisterModule(wchar_t const *moduleName, wchar_t const *eventEmitterName, ReactMemberId<I>) noexcept;
-};
-
-} // namespace winrt::Microsoft::ReactNative
diff --git a/vnext/Microsoft.ReactNative.Cxx/NativeModules.h b/vnext/Microsoft.ReactNative.Cxx/NativeModules.h
index 9653e144ade..305709f3aa6 100644
--- a/vnext/Microsoft.ReactNative.Cxx/NativeModules.h
+++ b/vnext/Microsoft.ReactNative.Cxx/NativeModules.h
@@ -4,33 +4,40 @@
 #pragma once
 #include "winrt/Microsoft.ReactNative.h"
 
-#include <type_traits>
 #include "JSValueReader.h"
 #include "JSValueWriter.h"
-#include "ModuleMemberRegistration.h"
 #include "ModuleRegistration.h"
 #include "ReactPromise.h"
 
-// REACT_MODULE annotates a C++ struct as a ReactNative module.
-// It can be any struct which can be instantiated using a default constructor.
-// Note that it must be a 'struct', not 'class' because macro does a forward declaration using the 'struct' keyword.
-//
+#include <type_traits>
+
+// REACT_MODULE(moduleStruct, [opt] moduleName, [opt] eventEmitterName)
 // Arguments:
 // - moduleStruct (required) - the struct name the macro is attached to.
 // - moduleName (optional) - the module name visible to JavaScript. Default is the moduleStruct name.
 // - eventEmitterName (optional) - the default event emitter name used by REACT_EVENT.
 //   Default is the RCTDeviceEventEmitter.
+//
+// REACT_MODULE annotates a C++ struct as a ReactNative module.
+// It can be any struct which can be instantiated using a default constructor.
+// Note that it must be a 'struct', not 'class' because macro does a forward declaration using the 'struct' keyword.
 #define REACT_MODULE(/* moduleStruct, [opt] moduleName, [opt] eventEmitterName */...) \
   INTERNAL_REACT_MODULE(__VA_ARGS__)(__VA_ARGS__)
 
+// REACT_INIT(method)
+// Arguments:
+// - method (required) - the method name the macro is attached to.
+//
 // REACT_INIT annotates a method that is called when a native module is initialized.
 // It must have 'IReactContext const &' parameter.
 // It must be an instance method.
-//
+#define REACT_INIT(method) INTERNAL_REACT_MEMBER_2_ARGS(InitMethod, method)
+
+// REACT_METHOD(method, [opt] methodName)
 // Arguments:
 // - method (required) - the method name the macro is attached to.
-#define REACT_INIT(method) INTERNAL_REACT_METHOD_3_ARGS(Init, method, L"")
-
+// - methodName (optional) - the method name visible to JavaScript. Default is the method name.
+//
 // REACT_METHOD annotates a method to export to JavaScript.
 // It declares an asynchronous method. To return a value:
 // - Return void and have a Callback as a last parameter. The Callback type can be any std::function like type. E.g.
@@ -40,61 +47,63 @@
 // - Return non-void value. In JavaScript it is treated as a method with one Callback. Return std::pair<Error, Value> to
 //   be able to communicate error condition.
 // It can be an instance or static method.
-//
+#define REACT_METHOD(/* method, [opt] methodName */...) INTERNAL_REACT_MEMBER(__VA_ARGS__)(Method, __VA_ARGS__)
+
+// REACT_SYNC_METHOD(method, [opt] methodName)
 // Arguments:
 // - method (required) - the method name the macro is attached to.
 // - methodName (optional) - the method name visible to JavaScript. Default is the method name.
-#define REACT_METHOD(/* method, [opt] methodName */...) INTERNAL_REACT_METHOD(__VA_ARGS__)(, __VA_ARGS__)
-
+//
 // REACT_SYNC_METHOD annotates a method that is called synchronously.
 // It must be used rarely because it may cause out-of-order execution when used along with asynchronous methods.
 // The method must return non-void value type.
 // It can be an instance or static method.
-//
+#define REACT_SYNC_METHOD(/* method, [opt] methodName */...) INTERNAL_REACT_MEMBER(__VA_ARGS__)(SyncMethod, __VA_ARGS__)
+
+// REACT_CONSTANT_PROVIDER(method)
 // Arguments:
 // - method (required) - the method name the macro is attached to.
-// - methodName (optional) - the method name visible to JavaScript. Default is the method name.
-#define REACT_SYNC_METHOD(/* method, [opt] methodName */...) INTERNAL_REACT_METHOD(__VA_ARGS__)(Sync, __VA_ARGS__)
-
+//
 // REACT_CONSTANT_PROVIDER annotates a method that defines constants.
 // It must have 'ReactConstantProvider &' parameter.
 // It can be an instance or static method.
-//
-// Arguments:
-// - method (required) - the method name the macro is attached to.
-#define REACT_CONSTANT_PROVIDER(method) INTERNAL_REACT_METHOD_3_ARGS(Const, method, L"")
+#define REACT_CONSTANT_PROVIDER(method) INTERNAL_REACT_MEMBER_2_ARGS(ConstantMethod, method)
 
-// REACT_CONSTANT annotates a field that defines a constant.
-// It can be an instance or static field.
-//
+// REACT_CONSTANT(field, [opt] constantName)
 // Arguments:
 // - field (required) - the field name the macro is attached to.
 // - constantName (optional) - the constant name visible to JavaScript. Default is the field name.
-#define REACT_CONSTANT(/* field, [opt] constantName */...) INTERNAL_REACT_CONSTANT(__VA_ARGS__)(__VA_ARGS__)
-
-// REACT_EVENT annotates a field that helps raise a JavaScript event.
-// The field type can be any std::function like type. E.g. Func<void(Args...)>.
-// It must be an instance field.
 //
+// REACT_CONSTANT annotates a field that defines a constant.
+// It can be an instance or static field.
+#define REACT_CONSTANT(/* field, [opt] constantName */...) \
+  INTERNAL_REACT_MEMBER(__VA_ARGS__)(ConstantField, __VA_ARGS__)
+
+// REACT_EVENT(field, [opt] eventName, [opt] eventEmitterName)
 // Arguments:
 // - field (required) - the field name the macro is attached to.
 // - eventName (optional) - the JavaScript event name. Default is the field name.
 // - eventEmitterName (optional) - the JavaScript module event emitter name. Default is module's eventEmitterName which
 //   is by default 'RCTDeviceEventEmitter'.
-#define REACT_EVENT(/* field, [opt] eventName, [opt] eventEmitterName */...) \
-  INTERNAL_REACT_EVENT(__VA_ARGS__)(__VA_ARGS__)
-
-// REACT_FUNCTION annotates a field that helps calling a JavaScript function.
+//
+// REACT_EVENT annotates a field that helps raise a JavaScript event.
 // The field type can be any std::function like type. E.g. Func<void(Args...)>.
 // It must be an instance field.
-//
+#define REACT_EVENT(/* field, [opt] eventName, [opt] eventEmitterName */...) \
+  INTERNAL_REACT_MEMBER(__VA_ARGS__)(EventField, __VA_ARGS__)
+
+// REACT_FUNCTION(field, [opt] functionName, [opt] moduleName)
 // Arguments:
 // - field (required) - the field name the macro is attached to.
 // - functionName (optional) - the JavaScript function name. Default is the field name.
 // - moduleName (optional) - the JavaScript module name. Default is module's moduleName which is by default the class
 //   name.
+//
+// REACT_FUNCTION annotates a field that helps calling a JavaScript function.
+// The field type can be any std::function like type. E.g. Func<void(Args...)>.
+// It must be an instance field.
 #define REACT_FUNCTION(/* field, [opt] functionName, [opt] moduleName */...) \
-  INTERNAL_REACT_FUNCTION(__VA_ARGS__)(__VA_ARGS__)
+  INTERNAL_REACT_MEMBER(__VA_ARGS__)(FunctionField, __VA_ARGS__)
 
 namespace winrt::Microsoft::ReactNative {
 
@@ -110,32 +119,19 @@ template <template <class...> class TFunc, class... TArgs>
 struct IsCallback<TFunc<void(TArgs...) noexcept>> : std::true_type {};
 #endif
 
-// Finds how many callback the function has
-template <class TArgTuple>
-struct GetCallbackCount;
-
-template <>
-struct GetCallbackCount<std::tuple<>> {
-  constexpr static size_t Value = 0;
-};
-
-template <class TArg>
-struct GetCallbackCount<std::tuple<TArg>> {
-  constexpr static size_t Value = IsCallback<std::remove_const_t<std::remove_reference_t<TArg>>>::value ? 1 : 0;
-};
-
-template <class TArg0, class TArg1, class... TArgs>
-struct GetCallbackCount<std::tuple<TArg0, TArg1, TArgs...>> {
-  using TupleType = std::tuple<TArg0, TArg1, TArgs...>;
-  constexpr static size_t TupleSize = std::tuple_size_v<TupleType>;
-  constexpr static size_t Value =
-      (IsCallback<std::remove_const_t<std::remove_reference_t<std::tuple_element_t<TupleSize - 2, TupleType>>>>::value
-           ? 1
-           : 0) +
-      (IsCallback<std::remove_const_t<std::remove_reference_t<std::tuple_element_t<TupleSize - 1, TupleType>>>>::value
-           ? 1
-           : 0);
-};
+// Finds how many callbacks the function signature has.
+template <class... TArgs>
+constexpr size_t GetCallbackCount() noexcept {
+  using TupleType = std::tuple<std::remove_const_t<std::remove_reference_t<TArgs>>...>;
+  if constexpr (sizeof...(TArgs) >= 2) {
+    return (IsCallback<std::tuple_element_t<sizeof...(TArgs) - 1u, TupleType>>::value ? 1 : 0) +
+        (IsCallback<std::tuple_element_t<sizeof...(TArgs) - 2u, TupleType>>::value ? 1 : 0);
+  } else if constexpr (sizeof...(TArgs) == 1) {
+    return IsCallback<std::tuple_element_t<0, TupleType>>::value ? 1 : 0;
+  } else {
+    return 0;
+  }
+}
 
 template <class T>
 struct IsPromise : std::false_type {};
@@ -186,8 +182,7 @@ struct ModuleMethodInfo<TResult (TModule::*)(TArgs...) noexcept> {
     return false;
   }
 
-  constexpr static size_t CallbackCount =
-      Internal::GetCallbackCount<std::tuple<std::remove_reference_t<TArgs>...>>::Value;
+  constexpr static size_t CallbackCount = Internal::GetCallbackCount<TArgs...>();
   using ModuleType = TModule;
   using MethodType = TResult (TModule::*)(TArgs...) noexcept;
   using IndexSequence = std::make_index_sequence<sizeof...(TArgs) - (HasPromise() ? 1 : CallbackCount)>;
@@ -375,8 +370,7 @@ struct ModuleMethodInfo<TResult (*)(TArgs...) noexcept> {
     return false;
   }
 
-  constexpr static size_t CallbackCount =
-      Internal::GetCallbackCount<std::tuple<std::remove_reference_t<TArgs>...>>::Value;
+  constexpr static size_t CallbackCount = Internal::GetCallbackCount<TArgs...>();
   using MethodType = TResult (*)(TArgs...) noexcept;
   using IndexSequence = std::make_index_sequence<sizeof...(TArgs) - (HasPromise() ? 1 : CallbackCount)>;
 
@@ -729,6 +723,9 @@ struct ModuleFunctionFieldInfo<TFunc<void(TArgs...)> TModule::*> {
   }
 };
 
+template <int I>
+using ReactMemberId = std::integral_constant<int, I>;
+
 template <class TModule>
 struct ReactModuleBuilder {
   ReactModuleBuilder(TModule *module, IReactModuleBuilder const &moduleBuilder) noexcept
@@ -745,6 +742,11 @@ struct ReactModuleBuilder {
     m_eventEmitterName = eventEmitterName ? eventEmitterName : L"RCTDeviceEventEmitter";
   }
 
+  void ModuleName(wchar_t const *moduleName, wchar_t const *eventEmitterName = nullptr) noexcept {
+    m_moduleName = moduleName;
+    m_eventEmitterName = eventEmitterName ? eventEmitterName : L"RCTDeviceEventEmitter";
+  }
+
   void CompleteRegistration() noexcept {
     // Add REACT_INIT initializers after REACT_EVENT and REACT_FUNCTION initializers.
     // This way REACT_INIT method is invoked after event and function fields are initialized.
@@ -775,45 +777,51 @@ struct ReactModuleBuilder {
   }
 
   template <class TMethod>
-  void RegisterInitMethod(TMethod method, wchar_t const * /*name*/ = nullptr) noexcept {
+  void RegisterInitMethod(
+      TMethod method,
+      wchar_t const * /*unused*/ = nullptr,
+      wchar_t const * /*unused*/ = nullptr) noexcept {
     auto initializer = ModuleInitMethodInfo<TMethod>::GetInitializer(m_module, method);
     m_initializers.push_back(std::move(initializer));
   }
 
   template <class TMethod>
-  void RegisterMethod(TMethod method, wchar_t const *name) noexcept {
+  void RegisterMethod(TMethod method, wchar_t const *name, wchar_t const * /*unused*/ = nullptr) noexcept {
     MethodReturnType returnType;
     auto methodDelegate = ModuleMethodInfo<TMethod>::GetMethodDelegate(m_module, method, /*out*/ returnType);
     m_moduleBuilder.AddMethod(name, returnType, methodDelegate);
   }
 
   template <class TMethod>
-  void RegisterSyncMethod(TMethod method, wchar_t const *name) noexcept {
+  void RegisterSyncMethod(TMethod method, wchar_t const *name, wchar_t const * /*unused*/ = nullptr) noexcept {
     auto syncMethodDelegate = ModuleSyncMethodInfo<TMethod>::GetMethodDelegate(m_module, method);
     m_moduleBuilder.AddSyncMethod(name, syncMethodDelegate);
   }
 
   template <class TMethod>
-  void RegisterConstMethod(TMethod method, wchar_t const * /*name*/ = nullptr) noexcept {
+  void RegisterConstantMethod(
+      TMethod method,
+      wchar_t const * /*unused*/ = nullptr,
+      wchar_t const * /*unused*/ = nullptr) noexcept {
     auto constantProvider = ModuleConstantInfo<TMethod>::GetConstantProvider(m_module, method);
     m_moduleBuilder.AddConstantProvider(constantProvider);
   }
 
   template <class TField>
-  void RegisterConstant(TField field, wchar_t const *name) noexcept {
+  void RegisterConstantField(TField field, wchar_t const *name, wchar_t const * /*unused*/ = nullptr) noexcept {
     auto constantProvider = ModuleConstFieldInfo<TField>::GetConstantProvider(m_module, name, field);
     m_moduleBuilder.AddConstantProvider(constantProvider);
   }
 
   template <class TField>
-  void RegisterEvent(TField field, wchar_t const *eventName, wchar_t const *eventEmitterName = nullptr) noexcept {
+  void RegisterEventField(TField field, wchar_t const *eventName, wchar_t const *eventEmitterName = nullptr) noexcept {
     auto eventHandlerInitializer = ModuleEventFieldInfo<TField>::GetEventHandlerInitializer(
         m_module, field, eventName, eventEmitterName ? eventEmitterName : m_eventEmitterName);
     m_moduleBuilder.AddInitializer(eventHandlerInitializer);
   }
 
   template <class TField>
-  void RegisterFunction(TField field, wchar_t const *functionName, wchar_t const *moduleName = nullptr) noexcept {
+  void RegisterFunctionField(TField field, wchar_t const *functionName, wchar_t const *moduleName = nullptr) noexcept {
     auto functionInitializer = ModuleFunctionFieldInfo<TField>::GetFunctionInitializer(
         m_module, field, functionName, moduleName ? moduleName : m_moduleName);
     m_moduleBuilder.AddInitializer(functionInitializer);
diff --git a/vnext/Microsoft.ReactNative.Cxx/ReactMemberInfo.h b/vnext/Microsoft.ReactNative.Cxx/ReactMemberInfo.h
deleted file mode 100644
index fef9e0ff9a0..00000000000
--- a/vnext/Microsoft.ReactNative.Cxx/ReactMemberInfo.h
+++ /dev/null
@@ -1,17 +0,0 @@
-// Copyright (c) Microsoft Corporation. All rights reserved.
-// Licensed under the MIT License.
-
-#pragma once
-#ifndef MICROSOFT_REACTNATIVE_REACTMEMBERINFO
-#define MICROSOFT_REACTNATIVE_REACTMEMBERINFO
-
-#include "winrt/Microsoft.ReactNative.h"
-
-namespace winrt::Microsoft::ReactNative {
-
-template <int I>
-using ReactMemberId = std::integral_constant<int, I>;
-
-} // namespace winrt::Microsoft::ReactNative
-
-#endif // MICROSOFT_REACTNATIVE_REACTMEMBERINFO
diff --git a/vnext/Microsoft.ReactNative.Cxx/StructInfo.h b/vnext/Microsoft.ReactNative.Cxx/StructInfo.h
index 298c2851ff4..e68c9e29673 100644
--- a/vnext/Microsoft.ReactNative.Cxx/StructInfo.h
+++ b/vnext/Microsoft.ReactNative.Cxx/StructInfo.h
@@ -7,12 +7,23 @@
 
 #include "winrt/Microsoft.ReactNative.h"
 
-#define REACT_STRUCT(type)                                                           \
-  struct type;                                                                       \
-  winrt::Microsoft::ReactNative::FieldMap GetStructInfo(type *) noexcept {           \
-    winrt::Microsoft::ReactNative::FieldMap fieldMap{};                              \
-    winrt::Microsoft::ReactNative::CollectStructFields<type, __COUNTER__>(fieldMap); \
-    return fieldMap;                                                                 \
+// We implement optional parameter macros based on the StackOverflow discussion:
+// https://stackoverflow.com/questions/3046889/optional-parameters-with-c-macros
+// Please refer to it if you want to understand it works.
+#define INTERNAL_REACT_GET_ARG_3(arg1, arg2, arg3, ...) arg3
+#define INTERNAL_REACT_RECOMPOSER_3(argsWithParentheses) INTERNAL_REACT_GET_ARG_3 argsWithParentheses
+
+//
+// These macros are internal implementation details for REACT_STRUCT and REACT_FIELD macros.
+// Please skip below to read about REACT_STRUCT and REACT_FIELD macros.
+//
+
+#define INTERNAL_REACT_STRUCT(structType)                                                  \
+  struct structType;                                                                       \
+  winrt::Microsoft::ReactNative::FieldMap GetStructInfo(structType *) noexcept {           \
+    winrt::Microsoft::ReactNative::FieldMap fieldMap{};                                    \
+    winrt::Microsoft::ReactNative::CollectStructFields<structType, __COUNTER__>(fieldMap); \
+    return fieldMap;                                                                       \
   }
 
 #define INTERNAL_REACT_FIELD_2_ARGS(field, fieldName)                      \
@@ -23,12 +34,25 @@
     fieldMap.emplace(fieldName, &TClass::field);                           \
   }
 
-#define INTERNAL_REACT_FIELD_1_ARGS(field) INTERNAL_REACT_FIELD_2_ARGS(field, L## #field)
-#define INTERNAL_REACT_FIELD_3RD_ARG(arg1, arg2, arg3, ...) arg3
-#define INTERNAL_REACT_FIELD_RECOMPOSER2(argsWithParentheses) INTERNAL_REACT_FIELD_3RD_ARG argsWithParentheses
+#define INTERNAL_REACT_FIELD_1_ARG(field) INTERNAL_REACT_FIELD_2_ARGS(field, L## #field)
 #define INTERNAL_REACT_FIELD(...) \
-  INTERNAL_REACT_FIELD_RECOMPOSER2((__VA_ARGS__, INTERNAL_REACT_FIELD_2_ARGS, INTERNAL_REACT_FIELD_1_ARGS, ))
-
+  INTERNAL_REACT_RECOMPOSER_3((__VA_ARGS__, INTERNAL_REACT_FIELD_2_ARGS, INTERNAL_REACT_FIELD_1_ARG, ))
+
+// REACT_STRUCT(structType)
+// Arguments:
+// - structType (required) - the struct name the macro is attached to.
+//
+// REACT_STRUCT annotates a C++ struct that then can be serialized and deserialized with IJSValueReader and
+// IJSValueWriter. With the help of REACT_FIELD it generates FieldMap associated with the struct which then used by
+// ReactValue and ReactWrite methods.
+#define REACT_STRUCT(structType) INTERNAL_REACT_STRUCT(structType)
+
+// REACT_FIELD(field, [opt] fieldName)
+// Arguments:
+// - field (required) - the field the macro is attached to.
+// - fieldName (optional) - the field name visible to JavaScript. Default is the field name.
+//
+// REACT_FIELD annotates a field to be added to FieldMap which then used by ReactValue and ReactWrite methods.
 #define REACT_FIELD(/* field, [opt] fieldName */...) INTERNAL_REACT_FIELD(__VA_ARGS__)(__VA_ARGS__)
 
 namespace winrt::Microsoft::ReactNative {