Axis ( अक्ष ) is an imaginary line on which the Earth moves around from West to East . Two points on the Earth through which this axis passes are two poles – North Pole and South Pole . Another imaginary line called Equator (भूमध्य रेखा) running on the Earth divides it into two equal parts. The northern half of the earth is known as the Northern Hemisphere and the southern half is known as the Southern Hemisphere . They are both equal halves. All parallel circles from the equator up to the poles are called parallels of latitudes (अक्षांश) . Latitudes are measured in degrees . Equator represents the 0° latitude. Since the distance from the equator to either of the poles is one-fourth of a circle round the earth, it will measure ¼th of 360 degrees, i.e. 90° . Thus, 90 degrees north latitude marks the North Pole and 90 degrees south latitude marks the South Pole . All parallels north of the equator are called north latitudes . Similarly, all pa...