What methods can be used to implement parallel processing of tasks or threads in an application?

In Android, there are several approaches for parallel task or thread processing:

• AsyncTask (deprecated, but still common in legacy code) — for simple background tasks with UI updates.
• Thread and Runnable — basic tools for creating and starting threads.
• Handler and HandlerThread — for message processing and executing tasks in a separate thread.
• ExecutorService — a more flexible and powerful way to manage thread pools.
• Coroutine (Kotlin) — a modern and convenient way for asynchronous programming with support for cancellation and thread management.
• WorkManager — for deferred and guaranteed background tasks that should run even after app restarts.

Example using ExecutorService:

ExecutorService executor = Executors.newFixedThreadPool(4);
executor.execute(() -> {
    // Background task
    doBackgroundWork();
});
executor.shutdown();