YouTube is a video-sharing website headquartered in San Bruno, California, United States. The service was created by three former PayPal employees in February 2005. In November 2006, it was bought by Google for US$1.65 billion. YouTube now operates as one of Google's subsidiaries. The site allows users to upload, view, rate, share and comment on videos, and it makes use of WebM, H.264/MPEG-4 AVC, and Adobe Flash Video technology to display a wide variety of user-generated and corporate media video. Available content includes video clips, TV clips, music videos, movie trailers and other content such as video blogging, short original videos, and educational videos.
Most of the content on YouTube has been uploaded by individuals, but media corporations including CBS, the BBC, Vevo, Hulu, and other organizations offer some of their material via YouTube, as part of the YouTube partnership program. Unregistered users can watch videos, and registered users can upload videos to their channels. Videos considered to contain potentially offensive content are available only to registered users affirming themselves to be at least 18 years old.(Wikipedia)