How much traffic is generated in split screen mode?

[Felix E. Klee]

Hi,

I wonder what traffic is generated when 
    I have a split screen session with a shell running in one of the
    regions
and 
    I hit enter in that shell.

If I were running in full screen mode, I assume that only a new line 
is sent to the terminal which then scrolls up. But what happens in 
the above case?

Felix