Why do we say "Roger"?

why in all kinds of radio transmissions do we confirm we heard something said by saying “roger”?

From where does this habit originate??

Not a habit at all.

“Roger"means” recieved in voice-radio communication.

It was universally selected as less probable to be confused
with other words which can sound like recieved in unfriendly radio conditions.

Incidentally,one can ‘roger’ a message and one can 'Out’from communication but never does one"Roger and out".

Like the feller sez–it’s one or the other but it ain’t never both of 'em t’gether—nohow!


Check out…
SDMB - Who is Roger ?

I’m always amused in the movies or on TV when they say “over and out.” If I’m not mistaken, “over” means “I am keeping the line open for you to reply,” and “out” means “I am shutting the line off.” So “over and out” means, “talk all ya want, " I won’t be listening.”

Huh. So I guess it means the pilot’s slightly confused, and suddenly thinks he’s talking to his wife?