North is one of the four cardinal directions, specifically the direction that, in Western culture, is treated as the fundamental direction:

• North is used (explicitly or implicitly) to define all other directions.
• The (visual) top edges of maps usually correspond to the northern edge of the area represented, unless explicitly stated otherwise or landmarks are considered more useful for that territory than specific directions.

Definitions

North can mean:

Etymology

The word north is traced to the Old High German nord, and the Proto-Indo-European unit ner-, meaning "left" (or "under"). (Presumably a natural primitive description of its concept is "to the left of the rising sun".)

Latin borealis is from Greek boreas "north wind, north", in mythology (according to Ovid) personified as the son of the river-god Strymon, and father of Calais and Zetes; septentrionalis is from septentriones, "the seven plow oxen", a name of Ursa Maior. Greek arktikos "northern" is named for the same constellation (c.f. Arctic).

Other languages have sometimes more interesting derivations. For example, in Lezgian kefer can mean both 'disbelief' and 'north', since north of Muslim Lezgians there are areas inhabited by non-Muslim Slavic peoples. In many languages of Mesoamerica, 'north' means also 'up'.

Magnetic north and declination

Magnetic north is of interest because it is the direction indicated as north on a properly functioning (but uncorrected) magnetic compass. The difference between it and true north is called the magnetic declination (or simply the declination where the context is clear). For many purposes and physical circumstances, the error in direction that results from ignoring the distinction is tolerable; in others a mental or instrument compensation, based on assumed knowledge of the applicable declination, can solve all the problems. But simple generalizations on the subject should be treated as unsound, and as likely to reflect popular misconceptions about terrestrial magnetism.

Roles of north as prime direction

The visible rotation of the night sky around the visible celestial pole provides a vivid metaphor of that direction corresponding to up. Thus the choice of the north as corresponding to up in the northern hemisphere, or of south in that role in the southern, is, prior to world-wide communication, anything but an arbitrary one. On the contrary, it is of interest that Chinese culture even considered south as the proper top end for maps.

In Western culture:

• Maps tend to be drawn for viewing with either true north or magnetic north at the top
• Globes of the earth have the North Pole at the top, or if the earth's axis is represented as inclined from vertical (normally by the angle it has relative to the axis of the earth's orbit), in the top half.
• Maps are usually labelled to indicate which direction on the map corresponds to a direction on the earth,
• usually with a single arrow oriented to the map's representation of true north,
• occasionally with a single arrow oriented to the map's representation of magnetic north, or two arrows oriented to true and magnetic north respectively,
• occasionally with a compass rose, but if so, usually on a map with north at the top and usually with north decorated more prominently than any other compass point.
• Up is a metaphor for north. The notion that north should always be up and east at the right was established by the Greek astronomer Ptolemy. The historian Daniel Boorstin suggests that perhaps this was because the better-known places in his world were in the northern hemisphere, and on a flat map these were most convenient for study if they were in the upper right-hand corner.Fact: date=June 2008