Emacs has major modes for several variants of Lisp. They use the same editing commands as other programming language modes (see Programs). In addition, they provide special commands for executing Lisp expressions.
Emacs Lisp mode
The mode for editing Emacs Lisp source files. It defines
C-M-x to evaluate the current top-level Lisp expression. See Lisp Eval.
Lisp Interaction mode
The mode for an interactive Emacs Lisp session. It defines
C-j to evaluate the expression before point and insert its value in the buffer. See Lisp Interaction.
The mode for editing source files of programs that run in Lisps other than Emacs Lisp. It defines
C-M-x to evaluate the current top-level expression in an external Lisp. See External Lisp.
Inferior Lisp mode
The mode for an interactive session with an external Lisp which is being run as a subprocess (or inferior process) of Emacs. See External Lisp.
Like Lisp mode, but for Scheme programs.
Inferior Scheme mode
Like Inferior Lisp mode, but for Scheme.