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The streamer is connected to the net by wire or wi-fi. With Spotify Connect or Tidal Connect, their apps on your phone, pad or computer will control your streamer, which will connect directly to the source for the music stream. Just choose your streamer as player within the Spotify or Tidal app. The streamer must be compatible with the Connect feature, see specs. Hi-rez can vary - see specs. Qobuz Connect is reportedly in the works.
The quality of sound, wire vs wi-fi, is a hotbed of polarized opinion. As always, better gear gets better results. Be sure the streamer software supports your intended stream source to avoid Bluetooth. Supported sources can be directly accessed via the streamers app.