Hocky Field Dimensions
5-yard circle Shooting Circle / Penalty Circle Backline Sideline Long Corner Attacker Mark [Not any more] 23 Metre Line Half Line 23 Metres 5 Yard / 4.57m 14.63m Goal Penalty Spot 5 Metre Mark 10 Metre Mark 5m 19.2m

5-yard circle

The 5-yard circle outside the shooting circle is a dashed line that identifies the area five meters from the edge of the shooting circle.

Shooting Circle / Penalty Circle

The shooting circle in hockey, also known as the striking circle or "D", is a D-shaped area in front of each goal. It has two uses

1. Attacking players must enter it before shooting a goal.

2. In field hockey, a penalty corner, sometimes known as a short corner, is a penalty given against the defending team. It is predominantly awarded for a defensive infringement in the penalty circle or for a deliberate infringement within the defensive 23-metre area.

Backline

In field hockey, the backlines are the shorter perimeter lines of the rectangular field and are 55 m wide. It has many purposes like Marking

◉ Goal lines: The portion of the backline between the goal posts 

◉ Long corners: If the ball goes over the backline after being touched by a defender, the attacking team is awarded a free hit from the 23-meter line

◉ Penalty corner: If the defender deliberately plays the ball over the backline, the attacking team is awarded a penalty corner

Sideline

Hockey pitches are rectangular, The sideline in ground hockey, also known as field hockey, is used to define the boundary of the playing area, and to keep the ball in play. The sideline is 91.4 meters (100 yards) long. There must be a minimum of 2 meters (6 ft 7 in) of run-off at the sidelines.

Long Corner Attacker Mark [Not any more]

On each sideline there is also a mark 5m from the backline, which is the Long Corner Attacker's mark. (from where long corners were formerly taken) Its no longer Valid as now Long Corners are taken from 23 Metre Line

23 Metre Line

The 23-meter line in field hockey is a line that runs across the field 22.90 meters from each back line. It's also known as the 25 yard line. The 23-meter line is used for a number of purposes, including:

◉ Resuming play: When the ball goes over the back line, the attacking team can resume play from the 23-meter line. This is called a long corner. This Rule was Introduced in 2015!
◉ Marking the point for a free hit: If the defending team commits an offense before the 23-meter line, the attacking team is awarded a free hit. 
◉ Offside rule; The 23-meter line was used for the offside rule from 1987 until it was abolished in 1996
◉ Stating Line for Penalty Shootout: Penalty shootouts are used to decide the winner in a cup match when the two sides have finished the game with the same number of goals . The Attacker starts from the 23 metre line for it and shoots within the Shooting area

Half Line

A half-way line, parallel to the back line, divides the pitch in two. The start of each period of play and resumption of play following a goal starts with all players in the half they are defending.

Goal

The regulation width of a hockey goal is 3.66m (12ft) and the regulation height is 2.14m (7ft).

Penalty Spot

The penalty spot in field hockey is a circle with a diameter of 0.15 meters that is located 6.4 meters from the center of each goal. It's also known as the stroke mark. These marks identify the spot where penalty strokes are taken

5 Metre Mark

5m is the mark for the closest position in which a defender may stand in case of Penalty Corner.

10 Metre Mark

 10m is the mark from which an attacking team takes the penalty Corner.