Latitude is the angular distance of any object from the equator measured in degrees. The angular distance from the equator to itself is 0, thus the latitude at the equator is 0 °. If we move either up or down from the equator, our distance increases, and so does our angle to it. Eventually we reach either the North or South Pole. Standing on the these poles, places us at exactly a 90 ° angle to the equator.
At any location on Earth we can draw a circle around it, representing every point that is at the same latitude. If we were to cut the earth in half at the equator and place a large piece of paper in between the two halves, we would find that both halves were exactly the same size. As we move either up or down the Earth, cutting the planet into two pieces produces one large piece and one small piece. As we approach the poles, the large piece gets very big, while the small piece becomes much smaller. Drawing these imaginary lines at different latitudes produces what we call parallels. Although technically it is possible to draw an infinite number of parallels at any number of latitudes, there are a few which are important for you to understand as you study our planet.
The first of these is called the equator. The equator is located at 0 ° latitude. Going north from the equator we find the Tropic of Cancer. This parallel is located at 23.5 ° north. Continuing further northward we reach the Arctic Circle at 66.5 ° north. Continuing all the way to the top of the Earth at 90 ° latitude we encounter the North Pole. If we journey southward from the equator we will find the Tropic of Capricorn at 23.5 ° south. Continuing south we reach the Antarctic Circle at 66.5 ° south. Finally, at 90 ° south, we find the South Pole.