There are two types of BMX bike and styles.
Racing
Park/Freestyle/Flat/Vert/Ramp/Street/Trick/Nitro Circus
Racing is racing. Race bikes are light, fast, and will not do tricks. They jump in a fast forward manner and land as such. Carbon fiber does not like vertical drops as the mountain bike riders seem to find out. Race bikes are specialized. You don't need a race bike to race, but it sure helps.
Freestyle is a broad term encompassing what you thought BMX was. BMX originally was racing, then tricks came later. And then tricks became what everyone knows BMX as. Freestyle bikes are heavy duty meant for smashing, grinding, jumping, mega vert air, and doing Nitro Circus things. Freestyle bikes aren't as specialized as race bikes. You can race a freestyle bike and it's fun, but it is slower and will want to jump everything it can since it was designed to do that.