What is an isolate in Dart, and how does it fundamentally differ from a traditional operating system thread used for genuine concurrent execution in many other programming languages?

An isolate is Dart's own dedicated unit of genuine concurrent execution, running completely independently with its own entirely separate private memory heap that cannot ever be directly shared with or accessed by any other isolate, and this fundamentally differs from a traditional operating system thread found in many other languages, where multiple threads generally do share the exact same underlying memory space, meaning two separate isolates can only actually communicate with each other by explicitly passing serializable messages back and forth between them, an important architectural design choice that meaningfully eliminates entire categories of tricky, genuinely difficult to reliably solve threading bugs, such as a shared data race condition.

final receivePort = ReceivePort();
await Isolate.spawn(computeHeavyTask, receivePort.sendPort);
final result = await receivePort.first;