A text editor is a program used to create and change the contents of text files. Most operating systems have a text editor: DOS has edit, Windows has Notepad, MacOS has SimpleText.
Debian provides a large variety of text editors. vi and Emacs are the classic two, which are probably both the most powerful and the most widely used. Both vi and Emacs are quite complex and require some practice, but they can make editing text extremely efficient. Emacs runs both in a terminal and under the X Window system; vi normally runs in a terminal but the vim variant has a -g option that allows it to work with X. text editors
Simpler editors include nedit, ae, jed, and xcoral. nedit and xcoral provide easy-to-use X Window system graphical interfaces. There are also several vi variants. Additionally, you can find and a GNU Emacs variant called XEmacs.
This book does not cover the use of any particular editor in detail, though we will briefly introduce ae since it is small, fast, and can be found even on the Debian rescue disks, so it pays to know a bit about it for usage in a pinch. When you need to do more serious editing, check out vim or GNU Emacs. Emacs provides an excellent interactive tutorial of its own; to read it, load Emacs with the emacs command and type F1 t. Emacs is an excellent choice for new users interested in a general-purpose or programming editor.