Yes peas are a perfectly good vegetable. No they're not the same as snow or Sugar snap peas, they're sometimes called green peas or english peas. (Unless you're in the south where they might be the brown ones called field peas or black eyed peas.)
Peas are hard to find raw, usually people nowadays don't want to bother shelling them and they don't ship or last well so stores don't stock them. They're not like apples or cucumbers where you can just spray wax on them to make them look fresh. Sometimes you can find them in farm stands or farmers markets, but I rarely see raw peas in a grocery store.
Frozen store bought peas are blanched before being frozen, which means they're dumped in boiling water for a few seconds then quickly cooled down and frozen. If they didn't do this the enzymes in the peas would keep them ripening/rotting slowly while frozen, and they wouldn't last as long in the freezer. That's why you can't buy really raw frozen vegetables.
Unfortunately, it's the enzymes that you want to get by eating raw foods in the first place. So they're no longer raw, however they're still less cooked than if you took them out and cooked them before serving.
They're almost raw though, (way better than canned!) and still good for you. So, it's relative. They're not as good as really raw, but better than canned or cooked. And way better than junk food!
I used to give my kids a bowl of frozen peas to eat as a snack in summer. When my son went away to college he called me one day and told me he thought he'd been lied to all these years. I asked him about what (guiltily remembering that I lied about everything from Santa Claus to what would happen to him if he ever smoked) and he said he didn't think frozen peas were a Socially Acceptable Snack after all because his roommates were sitting around eating a bag of chips and he pulled a bag of peas out of the freezer and started eating them and they all thought that was weird.
He still eats frozen peas right out of the bag and frozen blueberries too. He's a weird healthy kid!