(written from a Production point of view)
Netflix is a streaming video-on-demand provider, based in the United States and available in over 190 countries worldwide.  Outside the United States and Canada, it is the first-run broadcaster of Star Trek: Discovery, with episodes premiering one day after their release on CBS All Access, starting on 25 September 2017.
The company also has rights to stream the six previous television series. The Star Trek films are available intermittently.
In April 2011, it was announced that the company had signed a two-year deal with CBS to begin streaming the various Star Trek series in the United States. Streaming of the remastered version of Star Trek: The Original Series, Star Trek: The Next Generation, Star Trek: Voyager, and Star Trek: Enterprise began 1 July 2011. By September 2011, Star Trek: The Animated Series was available as well, although it wasn't part of the original deal. Streaming of Star Trek: Deep Space Nine began on 1 October 2011. 
In Canada, Netflix made Star Trek: The Next Generation available in late 2012, then removed on 1 December 2013. It was re-added to Netflix Canada in July 2014, later to be taken off in early 2016. As part of the Discovery deal, all six series were made available on July 1, 2016.
On 18 July 2016, Netflix's exclusive deal for Discovery was announced.  The company beat off competition from Hulu and Amazon Prime to secure the rights.  The distribution deal also included worldwide streaming rights to the six previous television series, which were made available by the end of 2016.