The "rm" command helps you to remove files from a Git repository. It allows you to not only delete a file from the repository, but also - if you wish - from the filesystem.
Deleting a file from the filesystem can of course easily be done in many other applications, e.g. a text editor, IDE or file browser. But deleting the file from the actual Git repository is a separate task, for which git rm was made.
The name of a file (or multiple files) you want to remove. Naming the file you want to remove can be as simple as providing the filename / path to a single file. But you can also provide multiple filenames (delimited by spaces) or even a wildcard pattern (e.g. test.*).
Removes the file only from the Git repository, but not from the filesystem. By default, the git rm command deletes files both from the Git repository as well as the filesystem. Using the --cached flag, the actual file on disk will not be deleted.
Recursively removes folders. When a path to a directory is specified, the -r flag allows Git to remove that folder including all its contents.
No files are actually removed. With this option (or its shorthand -n notation), you will only see an output of the files that Git would remove - but no files are actually deleted.
Removing Files in Tower
In case you are using the Tower Git client, removing files is very easy: by selecting the "Move to Trash" option, Tower will automatically mark the file as "deleted" in Git. And if you change your mind, you can simply hit CMD+Z (or CTRL+Z on Windows) to restore the file!