I honestly don't know the difference, I'm still getting used to this whole bike-fixing-up business but I would say it probably doesn't have to be. I picked up an old Concord road bike beater to ride around campus this year, and while trying to true the wheel I managed to strip just about all the nipples and screws. They wouldn't tolerate any tiny bit of force and pretty much flaked apart when I tried to turn them. I'm pretty sure they were the stock wheels, and probably the first time the spokes had been tweaked. But at this point I'll take whatever I can get for fairly cheap.

BTW, just to clarify, I'm needing a rim that 27" tires will fit on, it should be around 25.5" in actual diameter. I'm sure it's probably referred to as a 27" wheel but I just wanted to make sure