This section describes key bindings, which map keys to commands, and keymaps, which record key bindings. It also explains how to customize key bindings, which is done by editing your init file (see Rebinding Keys in Your Init File).
Since most modes define their own key bindings, activating a mode might override your custom key bindings. A small number of keys are reserved for user-defined bindings, and should not be used by modes, so key bindings using those keys are safer in this regard. The reserved key sequences are those consisting of C-c followed by a letter (either upper or lower case), and function keys F5 through F9 without modifiers (see Modifier Keys).