Garbage collection (GC) is a form of automatic memory management found in many programming languages, such as Java, C#, Python, and Go. The garbage collector attempts to reclaim memory occupied by objects that are no longer in use by the program, which helps prevent memory leaks and other memory management errors that could lead to inefficient use of resources or application crashes.
In a language with garbage collection, the programmer does not need to explicitly free objects or memory blocks; instead, the garbage collector periodically scans the program's memory to identify objects that are no longer reachable through any references from the running program. Once an object is identified as "garbage," the memory it occupies can be freed and returned to the pool of available memory, making it available for other objects.
Garbage collection is designed to simplify memory management tasks for developers, reducing the risk of common errors such as double freeing, memory leaks, and dangling pointers. However, it can introduce overhead due to the resources needed to run the garbage collection process, potentially affecting the performance of the application. Different languages and runtime environments implement various garbage collection strategies, balancing the trade-offs between performance, memory usage, and programming simplicity.