The main difference between FRS (Family Radio Service) and GMRS (General Mobile Radio Service) is in it's range. FRS is only limited to 500 miliwatts which is not more than 1 mile. Obstacles within its transmission path will also further limit its effectiveness. Typically, GMRS has a range of up to 50 Watts although most walkies use only up to 1-5W. Hence these GMRS radios have better range than FRS, are higher powered and are also generally more expensive and higher quality than FRS walkies. One main downside about the GMRS walkies is that it requires a license to operate in the US.