It is a common editor present in every unix flavor. It is pronounced as “Vee Eye” commonly called as visual editor.
Visual editor has three basic modes as follows.

1) Insert mode
a) append mode
b) open mode
c) replace mode
d) change mode
2) Command mode
3) Execution mode

1) Insert mode:  In this mode VI editor accepts all input.To enter in this mode, we have to use keyboard key ( i ) and go out from this mode,we have to use (esc) key.

2) Command mode:  In this mode we can perform various operations such as saving the contents,quitting the editor,saving and quitting,copying and pastig the data,moving the data etc.

cursor movements
left direction :h
right direction : l
up direction : k
down direction: j

3) Execution mode: In this mode, we can perform various operations such as saving the contents,quiting the editor,saving and quiting,copying and passing the data,moving the data etc.