Because Grandma was at a loss when I was telling her about my tennis excursion today, I've decided to compile a list of helpful tennis terms to remember next time I mention it.
Raquet: The implement with which you strike the ball.
Just kidding.
Baseline: The very back line of the court. Serves and most ground strokes take place on or around the baseline.
Alleys: The two columns on the sides of the court. If the ball enters one of the alleys during singles, the ball is called as out and the point goes to the player on that side. However, in doubles, alleys are fair game to be played in.
Service boxes: The two boxes in the front half of the court. In order for a serve to be considered in and playable, the server must serve the ball into the service box diagonal from their position behind the baseline. The service boxes are also where the net player in doubles stands when their partner is serving.
Ground strokes: Hitting the ball after it has bounced. Forehands and backhands are ground strokes.
Love: Zero. You use it at the beginning of every game to indicate that neither player has scored any points yet ("Love serving love."). It's also used to indicate if one player hasn't won any games yet ("Four serving love, love-love.").
15: One. Some people just count from one to three, but most players indicate one point by saying 15.
30: Two.
40: Three.
Deuce: When the score comes to 40-40, this is called deuce. A deuce can be settled one of two ways. If you're not playing "ads" (advantages), then the person who wins the next point wins the game. However, if you are playing ads...
Advantage: If one player wins the point after deuce, they have the "advantage". If the server has the advantage, they call the score as "Ad In" or "Advantage Server"; however, if the receiver has the advantage, the score is called as "Ad Out" or "Advantage Receiver". If the server wins the advantage, but then loses the next point, it goes back to deuce (this also works vice versa if the receiver gains the advantage). The player to win the advantage and the point following it wins the game.
Forehand: The stroke used to hit the ball with the dominant hand. For most people, it's the one-handed stroke done with the right hand.
Backhand: The stroke used to hit the ball with the weaker hand. It's generally done with both hands (unless you're awesome and have a one-handed backhand) and done on the left side of the body.
Playing the net: When playing doubles, one player generally plays in the back of the court while one plays the front of the court by the net. This can also be done in singles when the player moves up the court closer to the net. It's generally done so the player can volley a shot into a difficult angle and win the point.
Volley: Striking the ball without swinging. Volleys are more of a punch than anything else. They're mostly done at half court and up at the net, but can be used in certain situations at the baseline.
Lob: Generally used as a defensive shot (can be offensive), lobbing is when the ball is hit high into the air as a return.
I hope this has proven helpful. If there are any other questions, I'll be sure to update this most useful of glossaries.