Bearing

A bearing, sometimes referred to as relative bearing, is a common way to describe a specific direction in space in relation to a starship. ( display graphic)

Uses
Bearings were used to define the direction at which another object in space was located in relation to the current orientation of the ship. Bearings were also used when the ship made a course correction in its current heading. Bearings have also been used by away teams on the surface of a planet to indicate a direction. 

Bearings were given in a combination of two 360-degree angles. For example:
 * "111-mark-14."
 * "341-mark-20. Range 12 kilometers."
 * "320 degrees-mark-2."
 * "240 degrees-mark-6, port."
 * "123 degrees-mark-18. Range 90 thousand kilometers."

Background information
The first use of the term bearing to indicate a direction occurred in Star Trek: The Original Series episode "Balance of Terror". The meaning of bearings has been further defined in the writer's guides and several reference books, such as Star Trek: The Next Generation Technical Manual (pg. 36).

Bearing 000-mark-0 is directly in front of the ship and bearing 180-mark-0 directly behind the ship. Coming about to bearing 090-mark-0 would be a sharp turn to the right or starboard. Coming about to bearing 270-mark-0 would be a sharp turn to the left or port. The second figure after the "mark" is the elevation angle. Coming about to bearing 000-mark-90 would be tilting the ship directly upwards and 000-mark-270 directly downwards.