re with a "gun" to "paint" an image on a luminescent screen at the wide end. The inside of the wide end is coated with phosphors that react to the electron beam by lighting up, thus creating a picture. CRTs are used in TV receivers, oscilloscopes, PC monitors, and video displays. In video cameras, they are part of the scanning mechanism. Community Antenna Television. Developed in 1958, this technology was first used to carry television programming to areas where television service was not available. The term is now used to refer to cable television; which is a method of distributing multi- channel television signals to subscribers via a broadband cable or fiber optics networks. Early systems were generally branch-and-tree types, with all programs transmitted to all subscribers, who used a channel selection switch to indicate which program they wanted. Constant Bit Rate. A feature offered with isochronous service and required for real-time interactive video and voice communications. Charge coupled device. Used in cameras and telecines as an optical scanning mechanism. It consists of a shift register that stores samples of analog signals. An analog charge is sequentially passed along the device by the action of stepping voltages and stored in potential wells formed under electrodes. The charge is moved from one well to another by the stepping voltages. Comité Consultatif International Radio- communications. An organization, part of the United Nations, that sets technical standards for international television systems as part of its responsibilities. The CCIR is now known as the ITU-R. CCIR Rec. 656 The international standard that defines the electrical and mechanical interfaces for digital TV that operates under the CCIR-601 standard. It defines the serial and parallel interfaces in terms of connector pinouts as well as synchronization, blanking and multiplexing schemes used in these interfaces. Glossary of Terms CCIR Rec. 601 An internationally agreed-upon standard for the digital encoding of component color telev