Bands are a ring of metal, which fit around the molars and sometimes premolars. The bands are selected from a range of sizes in order to find the lightest fitting band. The bands are sealed in position using dental cement that contains fluoride to prevent any decalcification during treatment.
The brackets hold the arch-wire against each tooth. The arch-wire fits into a slot in the bracket. Brackets may be attached directly to each tooth or to a band.
The main wires, or arch-wires, are shaped specifically to fit around the arch into the bracket slots. Teeth move from the pressure that is applied by the braces. That pressure comes from the arch-wire, which guides the direction of the movement.
An elastic is the tiny rubber ring that ties the arch-wire into the bracket.
Hooks are small attachments on the brackets used to attach elastics (rubber bands).
The coil spring fits between brackets and over the arch-wire.