Renaming files in Linux changes a file's identifier within the file system. Unlike simply moving a file to a different directory (which also uses the mv command), renaming alters the file's name while typically keeping it in its original location. This operation doesn't modify the file's actual content or metadata like permissions or timestamps unless specified by a tool. You can rename files visually using a graphical file manager or programmatically via the command line.

The primary command-line tool is mv, used as mv oldname.txt newname.txt to change an individual file's name. For bulk renaming multiple files at once, utilities like the Perl-based rename command are common. For example, rename 's/\.jpg$/\.png/' *.jpg converts all JPG extensions to PNG in the current directory. This is valuable for photographers standardizing formats or developers cleaning dataset filenames.

Key advantages are the speed and flexibility of command-line renaming, especially with patterns. However, caution is essential: accidentally overwriting existing files is possible, and complex patterns require careful syntax to avoid unintended changes. Always double-check critical commands using mv -i (interactive mode) or a dry-run option with rename -n first. Backup important data before bulk operations.