In terms of her in-game abilities, she's a tank that focuses more on defensive barriers than handing out heavy damage. Her Particle Cannon fires a short-range beam of devastation, and can also lob an explosive charge for area-of-effect damage.
Zarya backs that up with two barrier moves, which both shields either her or her teammates from incoming fire, and buffs up the range and damage of her cannon. Her Ultimate is 'Gravitation Surge', a bomb that draws in enemies and damages them over time.
She looks like a good choice for those who like heavy armour and damage-dealing, but prefer to be able to retain a little speed. You'll be able to try her out when the Overwatch beta goes live later this year. Sign up over on