Line judge: Line judges have the task of deciding whether a ball has landed in the court or outside. Their decisions can only be overruled by the umpire.

Lob: A lob is a ball hit in a high arc, usually over the opponent's head. For the most part it is played when the opponent is standing at the net.

Longline: A stroke played straight down the court, either along or adjacent to one of the sidelines.

Love: Zero in tennis language, e.g. love-thirty = 0-30.

Lucky Loser/Playback: In some knockout tournaments, one defeat does not automatically result in elimination. Beaten players have the chance to play against other such losers, with the winners being awarded places in later rounds. These players are known as "lucky losers."

Mini-break: When the server loses the point during a tie-break, this is referred to as a mini-break.

Net or Let: The call from the net-cord judge when a serve touches the top of the net.

Not up: The call from the umpire when a ball, having bounced twice, is dead.

Overhead: Describes a stroke played above the head, e.g. a smash.

Overrule: The umpire's option and privilege to correct a decision made by one of the judges.

Penalty points: Points deducted for unsporting behavior.

Placement: The ball is hit to a precisely chosen part of the court, usually one that the opponent cannot reach.

Seeding: A graded list of the best players entering a tournament. The best players are normally "seeded" before a tournament begins. This prevents these players from being drawn against each other - and knocking each other out - during the early rounds of the competition.

Semicontinental: A combination of the forehand and backhand grips. This grip can be used for most shots, but particularly for volleys, serves and smashes.

Serve or service: Every point begins with a serve. From a position behind the baseline, the server has to hit the ball diagonally over the net into the opponent's service court. Players get two attempts to serve the ball correctly in each point. In the first point of any game or set, the serve is played from the right-hand side of the court. After this the server alternates side (from right to left and vice-versa) at the start of every new point.

Server: The player who is currently serving.

Serve and volley: A tactic where players serve and then rush to the net with the aim of playing a winning volley off the opponent's return.

Service lines: The service line runs parallel to the net. Together with the center line and sideline, it demarcates the boundaries of the service courts.

Set: A set comprises at least six games. Matches are generally played over three or five sets.

Set point: The point needed to win a set.

Sidespin: Spin which causes the ball to rotate horizontally.

Sign in: When players enter their names for a tournament.

Slice: A slice shot differs from a "drive" in that the backspin applied keeps it in the air for longer, causing it to travel further before bouncing.

Slice serve: Side spin and topspin are applied to the serve, causing the ball to keep low and change direction after bouncing. For example, slice serves from right-handed players cut sharply away to the left. This serve is particularly well-suited to grass or indoor courts, because these surfaces slow the ball down less than hard courts.

Spin: The rotation of a ball resulting from special types of strokes like slice and topspin. Spin affects a ball's trajectory and the way it bounces.

Stringing: The elasticity of the strings depends on the tension with which the racquet is strung. In general, gut strings are more elastic than synthetic strings, as a result of which they are generally strung more tautly. Players who like to hit the ball fast and hard usually prefer tauter strings. Touch players, by contrast, tend to prefer slightly slacker stringing.

Stop volley: A volley where the player takes the pace off the ball, so that it drops softly on the other side of the net - making it difficult or impossible for the opponent to reach

Topspin: A stroke where the player hits the top surface of the ball, causing it to rotate forwards.

Touch: Sensitivity when hitting the ball.

Twist serve: A service played with topspin and side spin. The ball bounces awkwardly sideways and upwards from the service court.

Unforced error: An error made while under no pressure from the opponent, e.g. mishitting a ball.

Western: A way of holding the racket particularly for topspin forehand strokes. In this grip the ball of the thumb rests on the top right-hand edge of the handle.

Wildcard: Irrespective of their positions in the rankings, an organizer can invite one or more players to take part in a tournament, offering them wildcards. This gives event organizers the opportunity of offering places to promising young players, or alternatively to stars who have failed to register in time for the tournament.