Apple TV (stylised tv) is a digital media player and microconsole developed and marketed by Apple. It is a small piece of networking hardware that sends received media data such as video and audio to a TV or external display. Its media services include streaming media, TV Everywhere-based services, local media sources, and sports journalism and broadcasts. Second-generation and later models function only when connected via HDMI to an enhanced-definition or high-definition widescreen television. Since the fourth-generation model, Apple TV runs tvOS with multiple pre-installed apps.
https://en.wikipedia.org/wiki/Apple_TV