Final answer:
The Prime Meridian is the imaginary line designated as 0 degrees longitude, running through Greenwich, England, and it divides the Earth into the Eastern and Western Hemispheres. It is the starting point for measuring longitude and is crucial for navigation and cartography.
Step-by-step explanation:
The Prime Meridian is the meridian (an imaginary line) that passes through the Royal Observatory in Greenwich, England, and is considered 0 degrees longitude. It is commonly known as the zero longitude line and is used as a reference point from which the east-west location, or longitude, of any place on Earth is measured. The Prime Meridian divides the Earth into the Eastern and Western Hemispheres. All lines of longitude east of the Prime Meridian are numbered from 1 to 180 degrees east (E), and all lines to the west from 1 to 180 degrees west (W).
By international agreement, the Prime Meridian is set as the line of longitude from which all other longitudes are measured, providing a standard for global navigation and timekeeping. Latitude and longitude measurements are fundamental in cartography and navigation, allowing for precise location pinpointing across the globe.