Dividing up the globe
Four imaginary lines help describe how the Sun's position in the sky varies according to your latitude. The Tropic of Cancer and the Tropic of Capricorn are lines – 235° north and south of the Equator – between which the Sun will be vertically overhead at some point in the year.They get their names because the Sun is in the constellation Cancer when it is at its furthest north (in June), and in Capricorn when it is at its extreme south (in December). The term “the tropics” can also be used to refer to the area of the Earth that lies between the two.
At the other extreme are the Arctic and Antarctic Circles, 23.5° from the poles. They are the lines beyond which the Sun does not get above the horizon for some part of the year.The nearer you get to the poles, the more extreme things become. At the poles themselves, the Sun rises above the horizon as it crosses the Equator and stays there for six months until it is back at the Equator again. Then six months of darkness ensue, which is much less enjoyable.