Center Circle – A circular marking with a 10-yard radius in the “center” of the field from which kickoffs are taken to start or restart the game. Purpose: Simply a reference line for the referee and defenders. Defenders must be as least 10 yards away from the ball prior to start or restart.
Center Spot – The “center” of the center circle from which kickoffs are taken to start or restart the game.
Corner Arc – An arc or quarter-circle with a radius of 1 yard located at each of the 4 corners of the soccer field. Purpose: Also a reference line, the ball must be kicked from inside this arc on a corner kick.
Corner Flag – The flag located at each of the 4 corners of the soccer field, inside the corner area.
Defenders (or backs) – Players who work mainly in the defensive third of the field. They are primarily focused on stopping the opposition’s attackers from scoring.
End Line (or goal line) – The boundary line extending from corner to corner along its width at each end.
Forwards – Players who are responsible for most of a team's scoring. They play in front of the rest of their team (or in the attaching third of the field) where they can take most of the shots.
Field (or pitch) – The rectangular area where soccer matches are played.
Fullback – A rear defender.
Goal Area – The rectangular area (20 x 6 yd. on a full-size soccer field) marked within the penalty area (or inside the larger rectangle) and directly in front of goal. Purpose: Marks the area from which all goal kicks must be taken.
Goal Box – Commoner’s term for the goal area or sometimes the penalty area.
Goalkeeper (or keeper, goalie) – I bet you know this one. The player positioned directly in front of the goal who tries to prevent shots from crossing the goal line; the only player allowed to use their hands and arms, though only within the 18-yard penalty area.
Midfielders – Players generally positioned in the middle third of the field between the forwards and defenders. Their job is to link the defense and the offense through ball control and passing. They play both an attacking role and a defensive role.
Striker – Generally the same as a forward, though it sometimes refers to a forward that is his team’s primary scoring threat.
Sweeper – Not always used. In some formations, a single defender that plays closest to their own goal behind the rest of the defenders; a team's last line of defense in front of the goalkeeper.
Penalty area – The larger rectangle (18 x 44 yd. on a full size field) in front of the goal that includes the goal area. Purpose: Marks both where the goalkeeper is allowed to touch the ball with his hands AND the area where harsh fouls committed by the defending team result in penalty kicks.
Penalty Arc – The arc at the top of the penalty area. Purpose: Designates how far back all players must be away from the ball while a penalty kick is being taken.
Penalty Mark (or Spot) – The mark on the soccer field from which penalty kicks are taken.
Stopper – The player that defends or guards the best scorer on the attacking team, often the opposition's striker.
Touchline (or sideline) – The line that runs along the length of each side of the field. Commonly called the sideline in other sports.
Wingers – The outside forwards and midfielders (often the fastest players and best dribblers) who play on the sides of the field. Their primary task is to provide them with accurate crossing passes so they can shoot at the goal.