If you’re a fan of Blizzard’s newest (and arguably, soon to be most successful) IP, you’ve been following the very lengthy, teaser pack release that Blizzard’s new hero has come with. Building up to the relapse of the new hero, blizzard has been teasing for months now about who and what this new hero can do, along with her back story and personality.
The wait has been worth it. 

Sombra is a spicy female hacker, with the ability to shut down other heroes and turn the tide of battle with her unique abilities. Sombra takes pride in flanking and taking down the back line of the enemy team – players who have spent time with Tracer will feel right at home with Sombra. Sombra has access to two different movements abilities; one that allows her to go completely invisible and increase her speed, and another that allows her to teleport to a thrown beacon. 

I’ve posted a video detailing her abilities and their uses below. 
Blizzard has also put a lot of work into her backstory. With her official announcement, Blizzard released both a fully animated short with Sombra, as well as an animatic detailing Sombra’s backstory.
I’ve linked to both below. 
Like most heroes, Sombra is an easy to play, hard to master kind of deal. She is a blast to play, and is available via the PTR now, and will become available on the live servers this coming week.