It is the line at the back of the tennis court that is parallel to the service line and in between the two singles sidelines.
Baseline
The two longest outside lines on a tennis court are called the doubles lines or doubles sidelines.
You stand behind the white line at the back of the court. This is known as the base line.
The back of a badminton court is a back boundary line and long service line for singles.
in the middle of the court.
The line towards the middle of the court where beginers first serve at is called the foul line. When serveing the ball should be amimed at the foul line. To your back of that line is an out of bounds line, it tells the players that if a ball bounces out onto the red it is out! Al
On a tennis court there are five lines. The line all the way at the back is the base line, the one in the front is the service line, the line making the T shape is the center service line, the first line on the left or right is the ally line, and the second line on the left or right is the side line.
endline
The boundries of tennis are, in singles play, the inner court line. In doubles play, the boundries are the outer line. The line that someone serves behind is the base line.
it is the first horizontal line from the net.
Tennis court lines are referred to as the "baseline", "service line", "singles line", "doubles line", and "center line". There is also a small "center mark" protruding from the court in the middle of each baseline.