According to an aspect, a communication system includes at least one mobile communication device, at least one movable communication device, and a server. The mobile communication device includes: a first position information obtaining unit for obtaining position information of the mobile communication device; and a first communication unit for communicating with another communication device. The movable communication device includes: a second position information obtaining unit for obtaining position information of the movable communication device; and a second communication unit for communicating with another communication device. The server stores the position information through communication with the mobile communication device and the movable communication device, and transmits the stored position information to at least one of the mobile communication device and the movable communication device.