Personal radio services

Definition
Personal Radio Services provide short-range, low power radio for personal communications, radio signaling, and business communications not provided for in other wireless services. The range of applications is wide, spanning from varied one- and two-way voice communications systems to non-voice data transmission devices used for monitoring patients or operating equipment by radio control. Licensing and eligibility rules vary. Some personal radio services require a license grant from the FCC, while others require only that the equipment used is properly authorized under the FCC's rules.

Source
FCC, Personal Radio Services (full-text).