Vi Cheatsheet

:x	Exit, saving changes.
:w	Save file.
:q	Exit if no changes have been made.
:q!	Exit and undo any changes made.
r	Replace one character.
x	Delete character to the right of cursor.
i	Insert before cursor.
o	Open a new line below current line.
dd	Delete current line.

With Esc we can swap from command mode to input mode and viceversa.