in-line skate 
Reinforced boot with four wheels placed in a straight line; it is used to move around on a hard, relatively smooth surface.
in-line hockey skate
Skate that is similar to an ice hockey skate; it is made up of a semisoft leather or nylon boot with reinforced side panels.
in-line speed skate
Skate with a light low-cut soft boot that is often molded to the foot; it has five wheels to provide greater contact with the ground.
Skate with a plastic boot that is designed to provide maximum support and protect against impact when the skater is doing tricks.
Device that is attached to the sole of the boot to support the wheels.
Round object that turns on an axis so the skate can move backward or forward.
Part of the boot that covers the lower part of the leg; it is usually hinged at the ankle.
Cushioned, often removable lining that is designed for greater comfort inside the boot.