It stands for File System ChecK. The name is taken from the Unix fsck command, which is used to validate a file system. While Git is not technically a file system, it can be used analogously and the command name is a metaphor on this.
During the course of working with your Git repository, you may end up backing out of operations, and making other moves that cause intermediary blobs, and even some things that Git does for you to help avoid loss of information. Eventually (conditionally, according to the git gc man page) it will perform garbage collection and … Read more