Shoutbox

Now this is absolutely and off-forum, but if I post it in the General Discussions it has a way lower chance of being seen by a translator. sorry admins and mods (you have the power to delete & mode it though)

So in some Japanese movies, and on karate training, we sometimes use the -san postfix to someone's name. But what does it exactly mean?thats my question. Some say it's "student", some it's "Sir", some simply "Mister" or "boy". Could someone make light in my dumb head by posting the answer?