Early skate tricks consisted mainly of two-dimensional maneuvers (e.g. riding on only the front wheels (nose manual), spinning like an ice skater on the back wheels (a 360 pivot), high jumping over a bar, long jumping from one board to another (often over fearless teenagers lying on their backs), and slalom.

Around 1978, street riding was transformed by the invention of the first modern skateboarding trick by Alan "Ollie" Gelfand. An ollie is performed by popping the tail of the skateboard deck, sliding the front foot towards the nose and lifting up the back foot to level the skateboard out. This results in the skateboarder, along with his or her skateboard, lifting into the air. At first, none of Gelfand's companions believed it was possible to perform a feat like this, and they thought he was attaching his feet to the board somehow.

The trick was reinvented by Rodney Mullen in 1981, being transferred to the horizontal plane and used as a trick for freestyle skating (a style of skating popular in the seventies and eighties based on stationary maneuvers). Rodney Mullen also invented the ollie kickflip, which, at the time of its invention, was dubbed the "magic flip." No longer was the trick simply to fly from one place to another. On the way the board could be made to twist and flip. The development of these complex tricks by Rodney Mullen and others transformed skateboarding. Skateboarding went from being performed only on the street to the vertical tops of the half pipes (and other terrain like huge stairs (sets) and handrails).

The act of "ollieing" onto a rail or pole, and sliding along it on the trucks of the board, is known as grinding and has become a mainstay of modern skateboarding. Types of grinds include the 50-50 grind (balancing on the front and back truck while grinding a rail), the 5-0 grind (balancing on the back truck while grinding a rail, kind of like a manual) and the nose grind (balancing on the front truck while grinding a rail). There are various other grinds that involve touching both the trucks and the deck to the rail, ledge, or lip. The most common of these is the smith grind, in which the rider balances over the back truck while touching the outer middle of the board to the grinding surface in the direction from which he or she popped. Popping and landing on the back truck and touching the inner edge of the board, i.e. popping "over", is known as a feeble grind.

Portions reproduced from Wikipedia.com