It is the same model of Communication between two parties. General Mobile Radio Service or GMRS radio started in the 1960 when wireless communication was still a challenge. Comparing with the conventional old fashioned telephones this was an easier setup as no wires were required and could make contact with other parties without digging the whole town from one end to the other.
Just like many wireless services available you or the provider has pay a fee so that Federal Communications Commission, FCC can issue a License. However having different frequencies for operations we can still use the portable hand held for free without causing any problems and probably works best for at small radius around land, mountains or any other terrain. You can get the exact info by reading the owners manual when buying the product making it your responsibility to follow all applicable rules and regulations regarding FCC and GMRS Radio laws.