This mode has no mode-specific redefinitions or variable settings, so that each Emacs command behaves in its most general manner, and each option is in its default state. For editing text of a specific type that Emacs knows about, such as Lisp code or English text , you should switch to the appropriate major mode, such as Lisp mode or Text mode. Selecting a major mode changes the meanings of a few keys to become more specifically adapted to the language being edited. The ones which are changed frequently are TAB , DEL , and LFD . In addition, the commands which handle comments use the mode to determine how comments are to be delimited.
Many major modes redefine the syntactical properties of characters appearing in the buffer .
See section The Syntax Table . The major modes fall into three major groups. Text mode, Nroff mode, TeX mode and Outline mode are for editing English text . Most programming language major modes specify that only blank lines separate paragraphs. This is to make the paragraph commands useful.