“RFID” is a broad term that refers to Radio frequency ID. But not all RFIDs are created equal with differences in range and frequencies, and some are in fact proprietary. But there are number of main standards out there, for example FeliCa (made by Sony and very popular in Japan) and MIFARE (made by NXP and very popular in transportation and elsewhere) with tons of deployments. The Oyster card is based on MIFARE for example.
The following diagram shows on An Exploration of the NFC-related Elements on Mobile Handsets (click to enlarge):
Read the rest at the NFC/Touch Page.