The two upturned ends of your
skateboard. These are used for performing
ollies and
nollies. Traditionally, skateboards were
devoid of these features and were completely flat. Later a one-kick board was invented. This was satisfactory for a time, until the
pop shove it came into view. It was then very troublesome, for a 180 pop shove it would leave the kick out front, leaving only the choice of a
nollie. This is how the nollie was
invented.
Soon enough they got the idea that a two-kick board would be useful, and in 1990 the first two-kick boards were sold. Nowadays the concave you find in your board to prevent the board from snapping has made its way into the kicks, giving you less chance of snapping the kicks as well as the added bonus of more pop.