Fans of the comics should be familiar with Yellowjacket as one of the many, many personas that Dr. Henry "Hank" Pym has taken on over the years. However, just as Ultron's origins are being changed for the MCU, Yellowjacket is undergoing some alterations as well.
In a departure for this adaptation, the Yellowjacket moniker is actually going to be used by the villain of the film, Darren Cross (Corey Stoll), who will fight it out with the second Ant-Man from the comics, Scott Lang (Paul Rudd) rather than Pym.
It can be assumed that Yellowjacket will have the same powers as Ant-Man—namely size-shifting and the ability to talk to insects—and considering how similar the suits look to each other, that seems to help confirm that theory. However, it's possible that the extra stingers shown here may give Yellowjacket the edge in battle somehow and may even be where the Bio-Sting energy is fired from. I wouldn't put it past the creators of the film to be using Yellowjacket as a source of inspiration for the Wasp character, either, as the two are similar in more ways than one.