Key mapping refers to creating a shortcut for repeating a sequence of keys or commands. You can map keys to execute frequently used key sequences or to invoke an Ex command or to invoke a Vim function or to invoke external commands. Using key maps you can define your own Vim commands. Vim supports several editing modes - normal, insert, replace, visual, select, command-line and operator-pending. You can map a key to work in all or some of these modes. The general syntax of a map command is: