How do Handler and Looper objects work together to process messages in Android?

In Android, the objects Handler and Looper work together to organize message processing and task execution in a thread.

• Looper is an object that runs a message loop in a thread. It retrieves messages from the queue and passes them for processing.

• Handler is an object associated with a Looper that allows sending and processing messages and Runnable tasks in that Looper's queue.

When a Handler is created, it is linked to the Looper of the current thread (usually the main UI thread). When calling handler.post() or handler.sendMessage(), a message is placed in the Looper's queue. The Looper, in its cycle, retrieves messages and passes them back to the Handler for processing in the handleMessage() method.

Thus, the Handler serves as an interface for sending and processing messages, while the Looper provides a continuous cycle of processing these messages in the thread.