YouTube is a video sharing website created in 2005 that allows users to upload, view, rate, share, comment on, and add playlists to videos. It has become an effective digital marketing platform due to its large user base and the popularity of video content online. Some benefits of using YouTube for digital marketing include wide audience reach, search engine optimization capabilities, low costs, ability to engage customers, and potential for videos to go viral. The document then lists top digital marketing YouTube channels that provide content in the field.