The four cardinal directions, or cardinal points, are the four main compass directions: north, south, east, and west, commonly denoted by their initials N, S, E, and W respectively. Relative to north, the directions east, south, and west are at 90 degree intervals in the clockwise direction.
The ordinal directions (also called the intercardinal directions) are northeast (NE), southeast (SE), southwest (SW), and northwest (NW). The intermediate direction of every set of intercardinal and cardinal direction is called a secondary intercardinal direction. These eight shortest points in the compass rose shown to the right are:
West-northwest (WNW)
North-northwest (NNW)
North-northeast (NNE)
East-northeast (ENE)
East-southeast (ESE)
South-southeast (SSE)
South-southwest (SSW)
West-southwest (WSW)
Points between the cardinal directions form the points of the compass. Arbitrary horizontal directions may be indicated by their azimuth angle value.
Points of the compass#Compass points
The directional names are routinely associated with azimuths, the angle of rotation (in degrees) in the unit circle over the horizontal plane. It is a necessary step for navigational calculations (derived from trigonometry) and for use with Global Positioning System (GPS) receivers. The four cardinal directions correspond to the following degrees of a compass:
North (N): 0° = 360°
East (E): 90°
South (S): 180°
West (W): 270°
The intercardinal (intermediate, or, historically, ordinal) directions are the four intermediate compass directions located halfway between each pair of cardinal directions.
Northeast (NE), 45°, halfway between north and east, is the opposite of southwest.
Southeast (SE), 135°, halfway between south and east, is the opposite of northwest.
Southwest (SW), 225°, halfway between south and west, is the opposite of northeast.
Northwest (NW), 315°, halfway between north and west, is the opposite of southeast.