Echo vs @echo

In general echo will print whatever is written beside it.

Ex:

Echo "I am the king"

Output:

I am the king

But putting a @ at the start of a line prevents the command on that line from being shown (echoed) on the screen.

@echo off

basically means that you give a "silent" command (with the @) to not show any future commands echoed on the Screen anymore - without it, any command executed in a batch file would be shown on the screen. 

Example: 
@echo off <-- prevents further commands from being 'echoed' to the screen 
cd c:\windows <- change to the windows folder (you won't see any output of this!) 
echo you are now in the windows folder. <-- this prints "You are now in the windows folder." on the screen 

if you would leave out @echo off at the start, the screen would show the "cd c:\windows" on the screen as well. it would then also print the 'echo You are now in the windows folder.' command on the screen, followed by the printed text.

@ECHO OFF ensures that that the commands in your batch file are not printed; only their output is printed. 

The "@" in front of ECHO OFF ensures that that command itself is not printed.