Modes; Customizing Using Your .emacs File
Emacs was designed to be flexible, especially when you become an advanced user or if you are a programmer. The designers of Emacs realized that your needs will vary depending on what you are doing. For example, if you are writing English prose, you will be typing and editing in a different manner than if you are, say, debugging a computer program. One of the ways in which Emacs helps you is by acting slightly differently depending on what you are trying to do. For example, when you are typing a computer program, you will want to indent your lines differently than when you are composing an essay.