Multiple Export options. What do they do?

Okay, I'm gonna ask probably a dumb question thats been answered a million times.
Upon Export, you get a number of options for age and prp exports. My question is what do all of those different ones do. Selection as Age. Does that mean just what you have selected gets exported? I'm a little confused as to all the different export options. Someone mind filling me in.
Upon Export, you get a number of options for age and prp exports. My question is what do all of those different ones do. Selection as Age. Does that mean just what you have selected gets exported? I'm a little confused as to all the different export options. Someone mind filling me in.