Unlocked Phones

[MSL80]

Okay so I'm new to this unlocked gadget world and wondering if "unlocked" means just that. I have service with US Cellular which claims to be launching the Moto Q6 in August 07' sometime! (Have to wait and see about that) But I'm very much interested in purchasing the Moto Q and I'm wondering if anyone would be able to tell me whether if I purchased an unlocked moto q if I'd be able to use that phone with my current service provider. Does unlocked actually mean that it can be used with any network or what exactly should I be looking for? Plz help me out.......I'm in need of this phone and the only svc providers I know of off hand that offer this phone is sprint and verizon.