VI command Overview

Move cursor command 
H: move the cursor one character to the left
L: move the cursor one character to the right
Space: move the cursor one character to the right
Backspace: move the cursor one character to the left
K or Ctrl + P: move the cursor up a row
J or Ctrl + N: move the cursor down a row
Enter: move the cursor down a row
W or W: move one word to the beginning of the word to the right of the cursor.
B or B: move one word left to the beginning of the word
E or E: move one word to the end of the word to the right of the cursor.
): Move the cursor to the end of the sentence.
(: Move the cursor to the beginning of the sentence.
}: Move the cursor to the beginning of the paragraph
{: Move the cursor to the end of the paragraph
NG: move the cursor to the beginning of line N
N +: move the cursor down n rows
N-: Move n rows above the cursor
N $: move the cursor to the end of line N
H: move the cursor to the top line of the screen
M: move the cursor to the middle line of the screen
L: move the cursor to the last line of the screen
0: (Note the number is zero) move the cursor to the beginning of the current row
$: Move the cursor to the end of the current row

Screen tumble command
CTRL + u: half screen at the beginning of the file
CTRL + D: Flip the half screen to the end of the file
CTRL + F: Flip the screen to the end of the file
CTRL + B; open a screen at the beginning of the file
NZ: Rolls row n to the top of the screen. If n is not specified, the current row is rolled to the top of the screen.

Insert text commands
I: Before the cursor
I: at the beginning of the current row
A: After the cursor
A: At the end of the current row
O: open a new row under the current row
O: open a new row above the current row.
R: Replace the current character
R: Replace the current and subsequent characters until you Press ESC.
S: Starting from the current cursor position, replace the specified number of characters with the input text
S: delete a specified number of rows and replace them with the input text
NCW or NCW: modify a specified number of characters
NCC: modifies a specified number of rows.

DELETE command
Ndw or ndw: n-1 characters starting at and following the cursor
Do: Delete to the beginning of a row
D $: Delete to the end of the row
NDD: Delete the current row and the next n-1 row
X or X: delete a character. x deletes the character after the cursor, and X deletes the character before the cursor.
CTRL + u: delete text entered in input mode

Search and replace commands
/Pattern: Search for pattern from the beginning of the cursor to the end of the file
? Pattern: Search for pattern from the beginning of the cursor
N: Repeat the previous search command in the same direction.
N: Repeat the previous search command in the reverse direction.
: S/P1/P2/G: replace all p1 in the current row with P2.
: N1, N2s/P1/P2/G: replace all P1 from line N1 to line N2 with P2.
: G/P1/S // P2/G: replace all P1 files with P2.