It means it can be used on any network. Most phones are locked, so you can only use it on a specific network (like Verizon or Sprint).
My boyfriend and I just got iPhones through Verizon. They are the iPhone 4 and were $0.97 with a new two-year contract. The 4S was $89.97 with a new two-year contract. We pay $190 a month for two lines (unlimited talk/text) and 4GB of shared data, plus insurance. Posted via Mobile Device