Garbage collection is an automatic memory management process used by programming languages to reclaim memory that is no longer being used by a program. In languages like Java, C#, and Go, garbage collection periodically identifies and frees up memory allocated to objects or data structures that are no longer referenced by the program, thus preventing memory leaks and improving system performance.

The garbage collector typically runs in the background and analyzes the program’s memory usage, identifying objects that are no longer reachable by any part of the application. Once identified, these objects are removed, and the memory they occupied is returned to the system for reuse.

While garbage collection simplifies memory management for developers, it can introduce performance overhead, as the system must periodically pause execution to perform the garbage collection process. Various algorithms are used to optimize this process, such as mark-and-sweep and reference counting, to balance performance and memory efficiency.