Garbage collection is the process of reclaiming the memory that is no longer being used by an application. In the Java programming language, the process of garbage collection occurs automatically. When an object is no longer being used, the memory that was allocated for that object can be reclaimed and used for other purposes.

There are a few different ways that the Java Virtual Machine (JVM) can perform garbage collection. The most common method is through the use of a garbage collector. A garbage collector is a separate thread that runs in the background and is responsible for finding and removing objects that are no longer being used by the application.

Another way that garbage collection can be performed is through the use of weak references. A weak reference is a reference to an object that is not strong enough to prevent the object from being garbage collected. This means that if the only reference to an object is a weak reference, the object may be garbage collected even if it is still in use.

Overall, the purpose of garbage collection in Java is to help manage the memory usage of an application and ensure that resources are being used efficiently. It is an important aspect of Java programming, as it helps to prevent memory leaks and improve the performance of the application.