In sports broadcasting, a sports commentator (also known as sports announcer, sportscaster or play-by-play announcer) gives a running commentary of a game or event in real time, usually during a live broadcast, traditionally delivered in the historical present tense. Radio was the first medium for sports broadcasts, and radio commentators must describe all aspects of the action to listeners who cannot see it for themselves. In the case of televised sports coverage, commentators are usually presented as a voiceover, with images of the contest shown on viewers' screens and sounds of the action and spectators heard in the background. Television commentators are rarely shown on screen during an event, though some networks choose to feature their announcers on camera either before or after the contest or briefly during breaks in the action.