Various embodiments provide a communication method and a communications apparatus. In those embodiments, a terminal device receives first indication information and second indication information from a network device. The first indication information indicates a position of a first reference point, the second indication information indicates a first quantity, the first quantity is a quantity of offset units between the first reference point and a second reference point, and the second reference point is an endpoint of a first physical resource block (PRB). The terminal device determines a position of the first PRB based on the first indication information, the second indication information, and an identifier of a subcarrier corresponding to the first reference point. Therefore, the terminal device can complete, without learning of a system bandwidth, a process of determining a PRB corresponding to a start point of a PRB number in the system bandwidth.