Normal mode:
i: insert before character
a: append after character
o: open a new line below
I: insert before line
A: append after line
O: open a new line above
gi: to to last edit
Visual mode:
v: characters select
V: line select
Ctrl + v: block select
Command line mode:
:wq save and quit
:%s/old/new/g replace old string to new string in entile file
:s/old/new/g replace old string to new string in current line
Ctrl + a: move to start of line
Ctrl + e: move to end of line
Insert mode:
Ctrl + h: delete last character, similar to bacspace
Ctrl + w: delete last word
Ctrl + u: delete line