An apparatus that transmits and receives wireless power, includes a controller configured to determine whether the apparatus is to operate in a power reception mode or a power transmission mode based on a capacity of a battery of the apparatus, and a capacity of a battery of another apparatus. The apparatus further includes a resonator configured to receive power from the other apparatus in response to the apparatus being determined to operate in the power reception mode, and transmit power to the other apparatus in response to the apparatus being determined to operate in the power transmission mode.