Technically, yes, they're pincers, simply pincers. If you're a carpenter, they're carpenter's pincers; if a saddler, they're saddler's pincers; if an upholsterer, they're upholsterer's pincers.
It's not particularly a multi-tool. Mostly it does one thing -- pulling nails or tacks instead of using a claw hammer. My largest pair is 12 inches and my smallest is about 4 inches. The pair I use most often is 6 inches.