What does "longitude" measure?

Longitude measures the distance east or west of the prime meridian, which is an imaginary line that runs from the North Pole to the South Pole, dividing the Earth into the Eastern and Western Hemispheres.

Longitude is expressed in degrees, with the prime meridian at 0 degrees, extending up to 180 degrees east and 180 degrees west. This measurement helps in determining specific locations on the Earth's surface in relation to the prime meridian. Understanding longitude is vital for navigation and mapping, as it provides a system for pinpointing exact locations across the globe.

The distinction between longitude and latitude is significant, as latitude measures the distance north or south of the equator, while longitude is concerned with east-west positioning relative to the prime meridian.