PCD (Proximity Coupling Device) is the generic term for readers within ISO/IEC 14443. The PCD is emitting an electromagnetic field and able to model all requests on the carrier frequency. All communication is initiated by the PCD and its range is about 10cm (proximity).
A Proximity Integrated Circuit Card (PICC) is a contactless Smart Card that is able to operate within a radius of approximately 10 cm of the card reader. As a passive card, it purchases power from the card reader device.