The rename tag refers to the action of giving a different name to either an existing file or to a copy of a file as part of some other operations (.e.g. remote copy, backup). Use this tag as well for questions related to the (perl) rename command.
Renaming is the action of giving a different name to an object (e.g. file, link or directory). It can also refer to the act of giving a new name to a copy of an object, while performing another operation such as uploading or remote copy.
The command renaming is
mv, but this is very basic and doesn't support functionality like renaming the extensions of a bunch of files¹. To rename objects using some pattern, either requires the shell to do pattern matching and replacement and then invoking
mv, or use of some other command like
rename (implemented in Perl).
¹ DOS command prompt users are used to be able to do
ren *.txt *.doc, something not built into