Yep, those are fairly typical features for most stereo systems.
It's basically just a wireless communication protocol that lets different devices talk to each other.
For instance, you could play songs on your smart phone and have them played over your car stereo via the wireless bluetooth connection. Essentially like connecting a cable via the AUX input, only without the wires.
Personally, I would rather put songs on a USB drive, but many folks have everything on their smart phones.
My wife and daughter both have stereos with USB ports. They load up music on a tiny USB drive, then plug it into their car stereo. Much more music than a CD and no skips. We haven't played a CD in our cars for years.
I don't know about current stereos (ours are about 10-15 years old) but ours are limited to 4GB flash drives. That's still a lot of music in a tiny package. You could always carry multiple flash drives if that's too limiting. :)
Our stereos are limited to MP3 files but I think newer ones support other formats like WMA, AAC, and FLAC.
I keep saying I'm going to upgrade my ancient stereo to one with a USB port. Unfortunately, every stereo on the market these days uses a knob for the volume control. My car rides fairly rough so trying to make small adjustments while bouncing around is kind of difficult. Worse yet, the volume knobs usually have different functions when you push them in, so I really mess things up when I hit a bump. :) My old Alpine stereo had separate volume up and volume down buttons, much easier to use with a stiff suspension. But, I don't really drive much anymore and generally only listen to the radio anyway. Low priority.
Just as examples, here are some cheap car stereos with USB ports that may work for you:
Anthony Watson