How do Main dispatcher and Default dispatcher differ when using coroutines in Kotlin?

In Kotlin coroutines, dispatchers determine which thread or thread pool will execute the coroutine.

• Main dispatcher — is the dispatcher that launches coroutines on the main (UI) thread. It is used for updating the interface and interacting with UI elements, where execution in the main thread is required.

• Default dispatcher — is the default dispatcher that uses a thread pool optimized for CPU-intensive tasks. It does not block the main thread and is suitable for background computations.

Example:

// Launching a coroutine on the main thread
CoroutineScope(Dispatchers.Main).launch {
    // update UI
}

// Launching a coroutine for background work
CoroutineScope(Dispatchers.Default).launch {
    // heavy computations
}

In summary, Main dispatcher is for the UI thread, Default is for background CPU tasks.