What degree of longitude does the Prime Meridian represent?

The Prime Meridian represents a degree of zero longitude because it serves as the reference line from which all other longitudes are measured. The concept of the Prime Meridian was established to create a standardized framework for timekeeping and navigation. It runs vertically from the North Pole to the South Pole and passes through the Royal Observatory in Greenwich, London. Longitudes to the east of the Prime Meridian are measured in degrees up to 180, while longitudes to the west are also measured up to 180, effectively providing a complete circle around the Earth. This makes zero degrees of longitude a foundational element in geography and global navigation systems.