TV timeline: Switching on the small screen
November 21 is World Television Day
Television is a mass medium for advertising, entertainment, news, and sports. It's estimated that virtually all households in the developed world now own a TV set, and in developing countries around 69% own at least one. That's a lot of viewing!
Switch on and click through the following gallery for a look at how television has evolved over the last 100 years or so, and be reminded of some of the small screen's memorable moments.