Text editor – vi
Similar to Windows notepad, vi is a screen-oriented text editor originally created for the UNIX operating system. Every UNIX user should know about it because someday you’re likely to find yourself on a system where you have no other choice but to use it.
Using vi is similar to using other editors in that it provides all general editor function like edit, cut, copy, paste, undo and etc. The difference is we use mouse in Windows GUI to move cursor onto where we are likely to edit while we edit files in vi from point to point by keyboard. So almost every UNIX beginner thinks vi is an unfriendly beast of an editor.