emacs
Emacs is, like vim, an extremely full-featured editor found on most UNIX- based systems. In addition to its editing capabilities, Emacs is extremely customizable, with additional functionality available in modules that let the Emacs interface do much more than just text editing. It’s relatively easy to do basic editing with, and has an incredible depth of functionality for the dedicated user to explore. Like vim, Emacs uses keystroke combinations to access its many different functional behaviors. These require memorization to be most useful, so Emacs is most useful for people who use the command line very often.
nano
nano is a simple command-line based editor. It’s a replacement for the pico editor, so instructions for using the pico editor can be used with nano. If you invoke the pico editor, you actually run nano. Nano is a good introduction to using a command-line based editor as it includes easy-to-follow on-screen help.
pico
vi
vi is always available whatever Linux distribution you have.
vim
vim is a vi-compatible text editor. It has many powerful enhancements for moving around, searching, and editing documents. Basic editing is simple to learn and there is much additional functionality to explore. Most functionality is accessed by typing combinations of keystrokes that trigger certain behavior. Vim, or the editor it’s modeled after, vi, is found in most UNIX-based operating systems. If you’ll be doing lots of editing from the command line, it’s a good editor to learn to use, but if you only use a command-line based editor occasionally, you can get by without learning it.