The wheels on a skate are specific to the surface you want to skate, for instance a softer wheel can be used outside for better rollover and a harder one can be used to slide and maneuver on smoother surfaces better.
These control the spin of your wheel and can greatly improve your push efficiency.
Your toestops control how quickly you can stop and turn, there also is a variant called a jam plug that is smaller and intended for jam skating.
These boots are pre-built and ready to roll.
Plain boots come with no plates or anything else, you either buy complete skates or you set up and build them with these.
These packages are the base of what you want in order to play roller derby, these include everything you need, from pads to skates themselves.
Skates to accompany you on your next adventure!
All the best brands in sizes from Junior to 2XLarge
They hold stuff, I don't know what else you need to know.
Anything and everything extra, from spare parts to Monkey Loob and Sport Gear spray.