Is Backfire Necessarily Bad?

[HotGMC]

I searched some threads, and didnt find anything about my particular "problem".

I just want to know if its necessarily a bad thing, my truck backfires when i rev it out(in park or neutral, not while in drive and smashing the gas) and usually its a few "Pop pop pops". i dont believe its my engine, but i only hear it below me and no from the engine area. i actually kind of like that Mean hoarse sound that the backfire makes. but could it be excess gas burning in the exhaust? or mabye oil or something. plus everytime i start up my truck, it shoots out a decent amount of smoke(not really thick) but its white.

figured some of you guys could give me a heads up. im going to get a video of my exhaust hopefully so i can post it on here. thanks again.