The orientation of a map is the relation between the directions drawn on a map and the realistic compass directions. The word “orient,” the root word in “orientation,” is derived from the Latin word “oriens,” meaning “east.”
The relationship between the way we now use “orientation” and “east” is due to how during the Middle Ages, many maps were drawn with east at the top. Today, most maps are drawn with north at the top, obviously.
But many maps from non-Western traditions are oriented different ways. Old Japanese maps used to depict the imperial palace at the top and center of the map. Certain Medieval European maps that were oriented east were centered with Jerusalem in the middle.
Often today, maps involving bodies of water are oriented around them. Cities bordering seas are sometimes drawn with the sea on top, and route and channel maps are sometimes oriented to the road or river they describe.
Probably the most notable example of a map being oriented not to the north is with the Arctic and Antarctic Circles, which are typically drawn with the pole at the center of the map because of how difficult it is to accurately draw them on a conventional map.