$ vi file   # open file
:w          # save (write)
:wq         # save and quit 
:x          # abbreviation of wq
:q!         # quit without save

h            # cursor left
j            # cursor down
k            # cursor up
l            # cursor right
0            # (zero) move to beginning of the line
$            # move to the end of the line
w            # move to the beginning of the next word
}            # skip to next section
H            # Jump to the beginning of the displayed screen
M            # Jump to the center of the displayed screen
L            # Jump to the bottommost line shown
CTRL-f       # Jump down one Page
CTRL-b       # Jump up one Page
CTRL-d       # Jump down halve a page
CTRL-u       # Jump up halve a page
gj           # For very long lines that wrap at the screen edge, jump up one line.
gk           # For very long lines that wrap at the screen edge, jump down one line.
%            # Jump to the next bracket character (){}[]

i           # insert at cursor position
a           # add after cursor position
o           # insert a line below
O           # insert a line above
12i <character>   # write the same character 12 times  ( type eight zero i dash <ESC> results in ------------)
y          # yank text (copy)
d        # delete
dt'     # delete everything to the character '
df'     # delete everything including character '
c       # copy line
y$       #copy to the end of the line (yank)
y5l     # yank five Characters from the cursor position to the right
yt(    # copy everything to the round bracket
d2w    #  delete two words
c2j     #change the next two lines
:undo or u
:redo or CTRL-R