WHO CHOOSES THE BETA TESTERS ON SOCOM3 & WTF IS BETA?

I been wondering if the BETA or whatever is like a demo or some shit like that and who gets the BETA disc is it the top players or WTF.

PS
Socom Tag:HELLBRINGER

There are several stages of making a game.. you start of making the game and when it gets to its first playable stage (ie you can play the game.. the levels wont be great, the graphics wont be great, AI wont be awesome but its playable) and thats called Alpha..

Then once the game is in a more playable state.. ie its the actual game, graphics are there, levels all follow on, the story works etc it can be classed as Beta.. now the game may work but there are always bugs in it, you might get stuck on a bin or something.. and so they developers recruit beta testers who’s job it is to find these bug and report them so all the major ones can be fixed.. there are always the odd minor bug here n there, and patches usually bring the odd one.

I dont know which person would recruit beta testers for SOCOM 3... if its for PS2 id imagine you’d need a special PS2.. i dont know because ive never tested a non PC game

I dont know why the choose certain people... id guess that its on beta experience, and for PCs, based on system specs (so they can test if it works on all grfx cards / motherboards etc)
Gaming ability would have something to do with it as you’d have to be able to get to all areas of the game without too much hastle.

But thats just a guess I cant be 100% sure

TY for the response bro.