Latitude and longitude are listed terms of degrees, minutes and seconds in reference to either the equator, for latitude, or Greenwich, England, for longitude. For instance, the latitude 48?22'34"N is read as 48 degrees, 22 minutes and 34 seconds North of the equator.
Latitude describes the number of degrees North or South of the equator. There are 90 degrees from the equator to either the North or South pole. One degree of latitude is approximately 69 miles. This distance varies due to the slightly oblong shape of the Earth.
Longitude describes the number of degrees East or West of the prime meridian line running through Greenwich, England. It is 180 degrees from the prime meridian to the international date line in the Pacific Ocean. Each degree of longitude is 69 miles apart at the equator, however this distance is reduced relative to the distance from the equator as longitude lines converge towards the North and South poles.
In both latitude and longitude measurements, there are 60 minutes in a degree and 60 seconds in a minute. Before latitude and longitude were standardized, other cultures had their own ways of determining their location. Ancient Chinese and Greek geographers both created their own grid systems. However, it was only in 1884 that measurements were standardized worldwide after Greenwich, England was selected for the prime meridian by an international conference.