Star Wars Rogue One will be the first Star Wars Stories movie.
One of the first things that happened after Disney bought Lucasfilm, was that the Lucasfilm Story Team made the decision to throw out the old Expanded Universe (moving it to the Legends label) and making it clear that none of that stuff was canon (aka part of the official approved Star Wars Universe).
At the time that was just the six movies, Star Wars Clone Wars, and the Star Wars Holiday Special. Okay, not the holiday special. Since then the official canon has really begun to grow.
The new canon is already getting pretty complex, there are games, comic books, books, TV shows and movies each with their own little corner of the Star Wars Universe. That might leave complete-ists a little confused as to what’s going on where. But don’t worry, thanks to this new timeline, we have details of everything that’s considered canon (based on what we learned up to and including the D23 Expo).
The graphic is pretty long, so I put it on the next page (click on page 2 below to see it).