After you have decided what your riding level is, you will need to decide what sort of riding you will be doing. Freestyle is a style of snowboarding that usually revolves around tricks, jumps, playing in the halfpipe, etc. Most people don't ride like this exclusively, and this is where Freeriding come in. This is the most common type of riding in which the rider enjoys the entire mountain, from trying tricks and jumps to floating in powder and cruising down the steeps. Alpine riding sometimes encompasses racing, and requires a completely unique set of gear.
Freestyle boots are typically softer and offer less support.
This is important because this type of riding demands a maximum ankle flexibility and freedom of movement to accommodate those daring jumps and tricks. At the speeds most alpine riders attain, they must have complete control and leverage over your board with an exact fit, and only a hard boot can truly offer this. A freeride boot falls somewhere in between the other two. It can be flexible and comfortable yet supportive and allows for a greater range of riding. By understanding the function of a snowboarding boot, you should be able to determine both your skill level and the type of riding you will be doing.