The tennis court is a rectangle on a flat surface, 78 feet (23.77m) long and, for singles matches, 27 feet (8.23 m) wide. For doubles matches, the court is 36 feet (10.97m) wide. It is divided in the middle by a net suspended between two net posts at a height of 3.5 feet (1.07m), dipping to a height of 3 feet (0.914m) at the centre. The ball typically must pass over the net when hit, but it is also legal to hit the ball around the net posts.

The boundaries of the court are defined by lines, which are there to show where the ball can be legally hit, and where the players can legally stand when serving or receiving a serve. Balls that land beyond the court boundaries on the first bounce after crossing the net are considered ‘out’, while balls that bounce either on or inside the lines are considered ‘in’.

The lines on the court have specific names and purposes:

• Baseline: marks the long boundaries of a court. The server must stand behind the baseline, between the centre mark and the sideline when serving.
• Singles sideline: marks the wide boundaries of a court when two singles players are playing.
• Doubles sideline: marks the wide boundaries of a court when doubles is being played.
• Doubles alley/tramline: the 4.5 feet (1.37m) gap between the singles sideline and the doubles sideline
• Service lines: located 21 feet (6.40 m) from each side of the net, parallel with the net.
• Centre service line: the line located parallel to the singles sidelines and halfway between them, creating two service boxes. A player’s serve must cross the net and land in the service box diagonally opposite in order to start a point.
• Deuce court: the half of the court located to the right of the centre mark and centre service line from the server and returner’s perspective.
• Ad court: the half of the court located to the left of the centre mark and centre service line from the server and returner’s perspective.
• Centre mark: located in the middle of the baseline, the mark indicates the central boundary of the deuce court and ad court for the server.

There is a wider array of shots in tennis. The fundamental shots are explained here:

• Serve: the serve (or service) is the first shot played in each game. The serving player tosses the ball in the air and hits it to land in the service box on the opposite – diagonal – side of the court. On each point, if a player misses their first serve, they may play a second serve.
• Groundstroke: the shot played after the ball has hit the ground. Groundstrokes are often played nearer the baseline, but can happen anywhere on the court.
• Volley: this shot is when the ball is hit by the player before it hits the ground. Volleys are often played close to the net, but can happen anywhere on the court.
• Forehand: a groundstroke or volley played with the palm of the racket hand facing the direction of the shot. Forehand groundstrokes are typically referred to as ‘forehands’.
• Backhand: a shot played with the back of the racket hand facing forward toward the direction of the shot. Backhand groundstrokes are typically referred to as ‘backhands’.

The following is a non-exhaustive list of terms used to describe shots in more detail:

• Ace: a serve which bounces in the correct service box that the returner (or receiver) fails to touch before the second bounce.
• Approach Shot: a shot played as the player is approaching (moving toward) the net.
• Backspin: this involves hitting the ball at an angle to cause a backward spin.
• Chip and Charge: a player hits a sliced approach shot, then runs towards the net to volley the opponent’s return.
• Crosscourt: hitting the ball to travel diagonally to the opponent’s side of the court (i.e. deuce court to deuce court, or ad court to ad court).
• Deep: hitting the ball that bounces near the opponent’s baseline.
• Down the line: a shot hit near, and roughly parallel to the sideline.
• Down the middle – a shot hit near and roughly parallel to the centre service line.
• Drop shot - a softly hit shot that lands close to the net, often played with backspin.
• Flat – hitting the ball little or no spin, often used in fast serves and groundstrokes.
• Half volley – hitting the ball just after it has bounced.
• Kick serve - the kick serve involves hitting the serve with lots of topspin, causing the ball to bounce high on the opponent's side.
• Lob: a shot designed to pass over an opponent’s head before landing in the court.
• Passing Shot - a shot hit past an opponent positioned near the net
• Slice - slice creates backspin on the ball, resulting in a lower bounce.
• Smash - a shot hit with the ball above head height hit with a downward trajectory towards the opponent’s court
• Topspin: a shot that creates a forward rotation on the ball, resulting in a higher bounce.
• Tweener: a shot hit between the legs. Also known as hotdog.

Tennis scoring is unique and has a language of its own. A match is made up of sets; a set is made up of games; and a game is made up of points. In each game, the score of the serving player or pair is always announced first.

A player or pair must win four points to win a game, with a margin of at least two points. Games are scored using the following point system:

• Love - in tennis, love means zero.
• 15 - one point.
• 30 – two points.
• 40 – three points.
• Deuce – this means that both players or pairs have scored three points each and are therefore level. A player or pair must win two consecutive points to win the game when the score is deuce.
• Advantage – when the score is at deuce, the next point won is known as advantage. Should the player or pair at advantage win the next point, they win the game. If the opponent wins the next point, the score returns to deuce.

A player or pair must win six games to win a set, with a margin of at least two games:

When both players or pairs have each won five games, (‘5-games-all’), the set will last for two more standard games, with one of two outcomes:

• One player or pair wins the next two games, and therefore wins the set 7-5

or

• The players or pairs win one game each and the set goes to a ‘tiebreak’. In a tiebreak, the first player or pair to win 7 points wins the set. A margin of two points in still needed, so if the score reaches 6-6 in the tiebreak, the tiebreak continues until one player or pair have won by two clear points (eg 8-6, 9-7, 10-8, etc). The winner of the tiebreak wins the set by a score of 7-6.

The majority of standard tennis matches are played as best-of-three sets (first player or pair to win two sets, also called three-set matches) while some men’s matches are played as best-of-five sets (first player or pair to win three sets, also called five-set matches).

The following terms are used to refer to specific points during a match:

• Game Point: A player is one point away from winning the game.
• Break Point: A break point occurs when the returner is one point away winning the game.
• Set Point: A player is one point away from winning a game and with it the set.
• Match Point: A player is one point away from winning a game and with it their second/third set to win the match.

The following terms describe the most common ways in which a point ends or must be restarted:

• Out: If the ball lands outside of the sidelines or baseline during a rally, the point goes to the other player.
• Fault: An unsuccessful serve is called a ‘fault’. On each point, the server gets two chances to execute a legal serve; after a fault on the first serve, a player gets a second serve.
• Double Fault: The server’s second serve is also a fault, and the point goes to the returner.
• Foot Fault: During the service motion, the server must stand behind the baseline and between the correct side of the centre mark and the sideline to serve. A foot fault is called when the feet touch the baseline or the court, or cross the centre mark or sideline.
• Service let: A ‘let’ is called when the serve hits the net but still lands in the correct service box, or the ball is served when the receiver is not ready. Rather than being considered a fault, the serve is replayed.
• Let: A let may also be called if a point is unexpectedly interrupted. In this case, the point is replayed, beginning with a first serve.

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Tennis can be played both indoors and outdoors on a variety of court surfaces, each with distinct characteristics. The three court surfaces featured at the Grand Slams are:

• Clay Courts: Clay is considered the ‘slowest’ surface in tennis, often leading to longer rallies. The courts are generally made of limestone base (or similar) and are covered in brick dust or shale. The most famous clay courts are those at Roland Garros in Paris, home to the French Open. Play on clay courts is distinguished by the need to slide on the loose surface. The European clay court season is usually played between April and June.
• Grass Courts: Grass is renowned for being a fast court surface, while the bounce can be unpredictable and low. Grass is best known internationally for The Championships, held each year at the All England Lawn Tennis Club in Wimbledon, London. The grass court season is played in June and July.
• Hard Courts: Hard courts are the most common type of tennis court, although the specification and the speed of the courts can vary greatly. Both the Australian Open, held in Melbourne each January, and US Open, played in New York in September, are played on hard courts.

There are many other tennis court surfaces used around the world, including carpet, astroturf, green clay, and parquet.