Whats RMVB format

I’ve looked at movies, and it says RMVB whats that? Does affect the size of the movie or something?
Answer #1
RMVB is Real Media format files. They have highly reduced sizes but also a lower quality than those files encoded using Xvid/Divx(AVI files). You need Real player or some alternative one (such as Real Alternative, Media Player Classic, VLC player, etc) to play them. They’re pretty good when you don’t want something to take up lots of space, such as full Anime series(just an example though). Good luck mate ^_^
Answer #2
Thanks alot for the help
Answer #3
You’er always welcome mate