XEmacs Reference Manual - Variables Go to the previous , next section. A variable is a Lisp symbol which has a value.
Variable names can contain any characters, but by convention they are words separated by hyphens.
A variable can also have a documentation string, which describes what kind of value it should have and how the value will be used. Lisp allows any variable to have any kind of value, but most variables that Emacs uses require a value of a certain type. Often the value has to be a string or a number. Emacs uses many Lisp variables for internal recordkeeping, as any Lisp program must, but the most interesting variables for you are the ones that exist for the sake of customization. These variables are called options .