Television (TV) is a telecommunication medium for transmitting and receiving moving images that can be monochromatic (shades of grey) or colored. Images are usually accompanied by sound. "Television" may also refer specifically to a television set, television programming, television transmission. The etymology of the word is derived from mixed Latin and Greek origin, meaning "far sight": Greek tele (τῆλε), far, and Latin visio, sight (from video, vis- to see, or to view in the first person. Commercially available since the late 1920s, the television set has become commonplace in homes, businesses and institutions, particularly as a source of entertainment and news. Since the 1970s the availability of video cassettes, laserdiscs, DVDs, and now HD-DVD Discs, have resulted in the television s