When you look at a map of the world you may see lines which are going round the earth at a horizontal angle, these are known as the latitude lines, they are also known as parallels. They are known as parallels because they are an equal distance apart, each line is approximately 69 miles apart. Try to imagine a ring around the earth, the one in the middle is the equator, this lies at 0° degrees, then they go all the way up to the North Pole which is 90° degrees and all the way down to the South Pole which is also at a 90° degree angle. The equator divides our planet into the northern and southern hemisphere.
Longitude is like latitude but longitude goes vertically down the planet at a 180° degree angle. Once again, the middle of the longitude lines are at 0° degrees and they go East to West becoming 180° degrees. The middle line runs through Greenwich (England) this allows for time-zones to be made.