What is a MethodChannel, and how does it let you actually invoke a specific native method from your Dart code and properly receive back its own returned result?

A MethodChannel is the genuinely most commonly used type of platform channel, letting your Dart code invoke a specific named native method by properly calling invokeMethod together with that particular method's own name and any genuinely required arguments, while the corresponding native side properly implements a matching method call handler that receives that same specific call, performs whatever genuine native work is actually required, and then properly returns its own resulting value back to Dart, and both sides genuinely need to agree consistently on that exact same specific channel name and each individual method's own expected name and its own particular argument format.

// Dart side
final result = await platform.invokeMethod('getDeviceModel');

// Android (Kotlin) side
when (call.method) {
  "getDeviceModel" -> result.success(Build.MODEL)
}