What methods can you use to implement asynchronous task execution in an application?

For asynchronous task execution in Android, several approaches can be used:

• AsyncTask (deprecated but still encountered sometimes)
• Handler and HandlerThread for managing threads and message queues
• Thread / Runnable — creating and starting new threads manually
• ExecutorService — thread pool for managing tasks
• Coroutines (Kotlin) — modern and convenient way of asynchronous programming
• RxJava — reactive programming with support for asynchrony

Example using Kotlin Coroutines:

import kotlinx.coroutines.*

fun fetchData() {
    GlobalScope.launch(Dispatchers.IO) {
        val data = networkRequest() // runs in background thread
        withContext(Dispatchers.Main) {
            updateUI(data) // updates UI on main thread
        }
    }
}