With theses digital devices, you can: connect to Wifi, connect to devices via networks such as 3G. play music in your car with Bluetooth, or use the cool LEDs included in the phone, but first, you need a carrier!
See, in order to make calls and connect to the web, you will need to be with a carrier. Companies that are wireless carriers are AT&T, Sprint, and T-Mobile. Note, there is an access fee in order for your new phone to setup activation. Or skip all this and have a prepaid cellular/wireless.
Once you have your plan set up, you now a subscriber to that company and are granted areas you can wirelessly connect, those are called service areas. Keep in mind if you want to call a landline phone, you pay an interconnection fee for the amount of airtime and talktime you are on with that phone.