Here is a good tutorial on the components of RFID:
1.2 RFID System
An RFID system is an integrated collection of components that implement an RFID solution.
An RFID system consists of the following components (in singular form) from an end-to-end perspective:
* Tag. This is a mandatory component of any RFID system.
* Reader. This is a mandatory component, too.
* Reader antenna. This is another mandatory component. Some current readers available today have built-in antennas
* Controller. This is a mandatory component. However, most of the new-generation readers have this component built in to them.
* Sensor, actuator, and annunciator. These optional components are needed for external input and output of the system.
* Host and software system. Theoretically, an RFID system can function independently without this component. Practically, an RFID system is close to worthless without this component.
* Communication infrastructure. This mandatory component is a collection of both wired and wireless network and serial connection infrastructure needed to connect the previously listed components together to effectively communicate with each other.
The Entire Tutorial can be found at:
RFID: A Technology Overview