Abstract: The charging system of the present disclosure includes: an electronic device having a first battery; and a charging device, in which the charging device includes a second battery that charges the first battery, a determination unit that determines whether or not the first battery is chargeable to a fully charged state, on the basis of a remaining charge amount of the first battery and a remaining charge amount of the second battery, and a charging control unit that controls a start of charging of the first battery by the second battery, on the basis of a result of the determination of the determination unit.

Abstract: The present disclosure relates to a communication device, a communication method, a program, and a communication system which can reduce power consumption relating to reception. A buffer amount of a reception buffer that buffers transmission data in a case of receiving the transmission data is monitored, the transmission data buffered in the reception buffer is not read until the buffer amount exceeds a predetermined threshold value, the transmission data buffered in the reception buffer is read in a case where the buffer amount exceeds the predetermined threshold value, and reception processing of the transmission data is executed. The present disclosure can be applied to the communication system.