
The "sidelines" are the white or colored lines which mark the outer boundaries of a sports field, running parallel to each other and perpendicular to the
goal lines.
The sidelines are also where the coaching staff and players out of play operate during a game. The area outside the sidelines is said to be
out of bounds
In sports, out of bounds (or out-of-bounds) refers to being outside the playing boundaries of the field. Due to the chaotic nature of play, it is normal in many sports for players and/or the ball to go out of bounds frequently during a game. T ...
. The term is predominantly in use in
American football
American football (referred to simply as football in the United States and Canada), also known as gridiron, is a team sport played by two teams of eleven players on a rectangular field with goalposts at each end. The offense, the team wit ...
,
Canadian football
Canadian football () is a sport played in Canada in which two teams of 12 players each compete for territorial control of a field of play long and wide attempting to advance a pointed oval-shaped ball into the opposing team's scoring area ( ...
,
field lacrosse
Field lacrosse is a full contact outdoor men's sport played with ten players on each team. The sport originated among Native Americans, and the modern rules of field lacrosse were initially codified by Canadian William George Beers in 1867. ...
and
basketball
Basketball is a team sport in which two teams, most commonly of five players each, opposing one another on a rectangular court, compete with the primary objective of shooting a basketball (approximately in diameter) through the defender's h ...
.

In
rugby union
Rugby union, commonly known simply as rugby, is a Contact sport#Terminology, close-contact team sport that originated at Rugby School in the first half of the 19th century. One of the Comparison of rugby league and rugby union, two codes of ru ...
,
rugby league
Rugby league football, commonly known as just rugby league and sometimes football, footy, rugby or league, is a full-contact sport played by two teams of thirteen players on a rectangular field measuring 68 metres (75 yards) wide and 112 ...
and
association football
Association football, more commonly known as football or soccer, is a team sport played between two teams of 11 players who primarily use their feet to propel the ball around a rectangular field called a pitch. The objective of the game is t ...
, they are known as
touch-line
The touch-line is the line on either side of the playing area of a game of rugby league, rugby union and association football. In many other sports it is called a side-line.
The continuation of the touch-line beyond the goal line ending at the ...
s. The foul line is a similar concept in
baseball
Baseball is a bat-and-ball sport played between two teams of nine players each, taking turns batting and fielding. The game occurs over the course of several plays, with each play generally beginning when a player on the fielding ...
. In
cricket
Cricket is a bat-and-ball game played between two teams of eleven players on a field at the centre of which is a pitch with a wicket at each end, each comprising two bails balanced on three stumps. The batting side scores runs by st ...
, the
boundary lines can be marked by a rope. Sports in which the playing surface is bounded by walls, such as
ice hockey
Ice hockey (or simply hockey) is a team sport played on ice skates, usually on an Ice rink, ice skating rink with Ice hockey rink, lines and markings specific to the sport. It belongs to a family of sports called hockey. In ice hockey, two o ...
,
box lacrosse
Box lacrosse, also known as boxla, box, or indoor lacrosse, is an indoor version of lacrosse played mostly in North America. The game originated in Canada in the 1930s, where it is more popular than field lacrosse. Lacrosse is Canada's officia ...
, and
indoor football, do not use sidelines; in these sports, coaches and reserve players are positioned in recessed benches behind the walls.
References
Terminology used in multiple sports
Association football terminology
American football terminology
Baseball terminology
Basketball terminology
Rugby league terminology
Rugby union terminology
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