The goal of a racer is to go fast and finish first. Racing frames are built as light and aerodynamic (thin) as possible. They’re also more compact and difficult to build.
Durability is a challenge for racing frames. If the racer crashes out, he’s not going to win the race. But additional strength usually equates to additional weight. The best racing frames strike a fine balance between these considerations.
One defining characteristic of today’s racing frames is the Stretched-X motor layout. These frames have the motors farther apart front-to-back than side-to-side. It’s hard to tell whether this offers any legitimate benefit, or whether it’s just another fashion trend. Enough top racers are flying Stretched-X that maybe there’s something to it.
Racing frames are more likely to use an under-slung battery. They can usually carry a GoPro if need be, but may be designed with the GoPro as an afterthought, rather than a necessity.
All of the “racing” frames on this page are intermediate to advanced builds. If you’re a beginner, you should buy one of the “freestyle” frames above and enjoy racing it. You won’t be as competitive as someone with a purpose-built racer, but you’ll still have a great time.