Universal Transverse Mercator (UTM) is a global spatial system based on the Transverse
Mercator projection. UTM divides the Earth into 60 equal zones, each being 6 degrees wide.
Each zone is bounded by lines of longitude extending from the North Pole to the South Pole.
Imagine an orange consisting of 60 segments. Each segment would be equivalent to a UTM
zone. A rectangular grid coordinate system is used in most map projections. These coordinates are
referred to as Eastings and Northings, being distances East and North of an origin. They are
usually expressed in metres.

Under the UTM system, each East and North coordinate pair could refer to one of sixty points on
Earth — one point in each of the sixty zones. Because of this, the zone number needs to be
quoted to ensure the correct point on Earth is being identified.