The Garage Band comment triggered me because that's the typical answer and always a indictment on someone's lack of knowledge on the topic.

Technically everyone that uses DJ equipment (most) at a show is a DJ, but DJ'ing only refers to the act of mixing songs together.

The distinction is if they do in fact produce their own music. But how do they do it? Do they just use samples or presets? Because many people also call themselves producers when they just throw shit together that professionals have made and sold. That takes pretty little talent as well.

A "real" producer (which are 95% of who you'll see streaming right now) create everything. They assemble the drums, they create the nosies (leads, melodies, etc) by utilizing synthesis/sound design. It takes years to learn how to sound design to a professional level. Then you throw in mixing which is a whole art form itself. Any band that records anything then has to have a mixing engineer do their thing which is then passed to a mastering engineer. As a producer you have to wear every one of these hats. The artist hat, the mixers hat, the engineers hat. So when your friend says he gets played to play his own music i'm hard pressed to believe that because of how long it takes to master all of those facets of creating a song where it's actually good enough and passable enough to hold up against professional songs he'd be mixing in his set as well.

He'd probably be making a damn good amount of money if he was in fact producing all his own shit and it was good enough.

If he is, then more power to him and I rescind my previous comment.