Garbage collection

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Garbage Collection

The term garbage collection comes from computer science where it refers to cleaning up unused memory (see [1]) in languages such as Lisp and Java where memory is allocated dynamically and not explicitly deallocated.

As it's used in this Wiki, garbage collection (abbreviated "GC") refers to cleaning up disk cache by removing files, or copies of files, that have been scheduled for deletion.

Internal copies of the file - whether a disk SE or one with a tape backend - can be created by the SE for optimisation purposes. A disk copy can be cleaned up because space is needed, or because its lifetime expires - either way, the process of removing such copies is garbage collection.