SPECIAL COMMAND IN COMPUTER

Insert commands

i -Insert before cursor

I -Insert at the begining of the current line (the line at which the cursor is placed)

a - Appends after cursor

A - Appends at the end of the current line 

o -Insert the blank line below the cursor line.

Delete commands

X - Delete a character at the cursor position.

<n>x - Delete specified number (n) of the character before the cursor position

dw -Deletes from cursor position to end of the current words .It stop at any punctuation (eg ",,) that appears with the word.

dw  : Some as dw but ignores any punctuation that appears with the word 

db   : Deletes from cursor position to beginning of the current word .It stop at any punctuation that appears with the word.

dB  : same as db but ignores any punctuation that appears with the word.

dd  : Delete current line.

<n>dd  : Delete specified number of lines(n) from the current line.

d[Enter]  : Delete current line and following line .

d0   : Delete all the character from the beginning of the current line to previous character of cursor position.

D   : Delete all the character from the current character to end of the current line

 Replace command 

r  : Replace single character at the cursor position .