What is the primary function of the command 'rsync'?

The command 'rsync' is primarily designed to synchronize files and directories between two locations, which can be on the same machine or between different machines over a network. It achieves this by transferring only the differences between the source and the destination, rather than copying the entire file each time. This makes 'rsync' highly efficient for backups and mirroring data, as it minimizes the amount of data that needs to be copied and speeds up the synchronization process.

Additionally, 'rsync' has various options that allow you to include features such as compression during transmission, preserving file permissions, and excluding certain files from the synchronization process. While it can facilitate backup operations, its core purpose is focused on the synchronization aspect. The command can also monitor changes in files to some extent, but its primary use case is effectively managing the synchronization of files and directories.