What are the fundamental skills for Tennis?

What are the fundamental skills for Tennis ?

Serve : This is the stroke that starts the play. The server stands behind the base-line and has two tries to send the ball into the diagonally opposite service court. The first serve in the match is made from the right side of the court, and the players then change sides after each point.
Ground-Stroke : It is also termed as passing shots. They are usually played from the base-line. It is used during rallies to provide a powerful and accurate attack. It can be played fore-hand or back-hand.
Volley: These strokes are made before the ball touches the ground. Volleys are usually made from close to the net. Half volley is played to low coming ball before it bounces.
Lob : It is the stroke in which the ball is sent high and far so that it bounces close to the base-line. It should be hit sufficiently high to pass over the opponent beyond his reach. It is usually played when opponent is close to net.
Smash : This powerful overhead stroke is in response to a lob and leaves little opportunity to respond.
Grip : There are many variations of grips, like continental, western and two handed grip (mainly used for backhand strokes).