This command is issued in order to delete files and directories. The -r flag removes directories recursively; it deletes the specified directory and all directories enclosed in that directory. The -f flag will supress the message that asks you to confirm a deletion.
lightning:~>rm explorer.exe
Removes the file called explorer.exe.
lightning:~>rm -rf generic
Assuming generic exists and it is a directory, this
command will remove generic and all directories and files contained
therein without promptin you to confirm deletion of every file.