Wikimedia Commons has media related to Internet television channels.

Within the context of internet television, a channel might be 1) a broadcast or cable TV station/network (e.g. CBS or CNN) which posts videos or live streams to its website or a video hosting website, 2) a user or group who live stream or upload videos to a video hosting website such as Youtube or Twitch (e.g. The Young Turks), or 3) a video on demand website (such as Netflix or Youtube) which is assigned a channel number by cable/satellite TV providers. Some video on demand services (e.g. Hulu, Viki or DramaFever) have channels on Youtube, but their own apps or websites would probably not be considered channels in and of themselves.