[Update]: The replay system has now arrived to the live servers alongside a whole bunch of other changes and bug fixes.
A little while ago Overwatch has introduced the very first version of the replay system. However, while the replays themselves work perfectly fine and are actually quite educational, the whole system was a little bit limited given that you could only watch your own replays.
Thankfully, this is no longer the case! After the most recent update, the replay system has now been extended to the current season of the Overwatch League. So if you ever wanted to see what exactly your favorite pro does at every moment of a match, or even how the battles as a whole play out from a different angle, you now have a chance to do just that!
The only catch is that the Overwatch League Replay Viewer is not a part of the basic game and will have to be downloaded separately. The whole process is fairly simple: just open up the BattleNet app, go into the Overwatch region drop-down settings, and then just select "Professional Viewer" from the dropdown menu. Install it onto your PC and you'll be good to go in no time!
If you've never used the replay system before and you're a bit overwhelmed by all of the options, you might also want to check out the official announcement as it has neat list of keybinds you can mess around with. Once mastered, they'll give you the ability to control just about every part of the system in what I must admit is a fairly simple way.
Have fun, and I hope you can learn a few new tricks!