Latitude of Polaris
Polaris is far from Earth. Thus, light from the North Star reaches parallel to the Earth. And since the earth is round, the latitude of the North Star varies depending on where it is observed.
Incidentally, the North Star is located in an extension of the Earth’s axis of rotation. Thus, the latitude of Polaris is equal to the latitude of the region where the observer is located.
In other words, for observers in the Arctic region, the latitude of the Polaris is 90 ° and for the observer in the equator region is 0 °. Therefore, if you measure the latitude of a Polaris in an area, it is the latitude of that area. Before GPS became popular, Polaris provided important clues to location and direction.