The present invention relates to a communication 
system and communication method which enable various types of 
near field communication, and a 
data processing apparatus. NFC communication apparatuses 1 to 3 have two features in that each can perform communication in two communication 
modes and that each can perform 
data transmission at a plurality of transfer rates. The two communication 
modes consist of a passive mode and an 
active mode. In the passive mode, between the NFC communication apparatuses 1 and 2, for example, the NFC communication apparatus 1 transmits data to the NFC communication apparatus 2 by modulating electromagnetic 
waves generated by itself, while the NFC communication apparatus 2 transmits data to the NFC communication apparatus 1 by performing load modulation on the electromagnetic 
waves generated by the NFC communication apparatus 1. Alternatively, in the 
active mode, either of the NFC communication apparatuses 1 and 2 transmits data by modulating electromagnetic 
waves generated by itself. The present invention can be applied to, for example, an IC card 
system, etc.