Final answer:
The Prime Meridian is the line of zero-degree longitude that passes through Greenwich, England and separates the Eastern and Western Hemispheres.
Step-by-step explanation:
Zero-degree longitude is also known as the Prime Meridian. The Prime Meridian is a geographical reference line that passes through the Royal Observatory in Greenwich, England and divides the Earth into the Eastern and Western Hemispheres. It is the starting point for measuring longitude, which extends 180 degrees eastward and 180 degrees westward.
Unlike parallels of latitude, which are defined by the angular distance north or south from the equator, meridians are perpendicular to the equator and meet at the poles. The Prime Meridian and the lines of longitude are crucial for navigation, timekeeping, and geographical reference.
The Equator, in contrast, is the line of 0 degrees latitude, while the Tropic of Cancer and the Tropic of Capricorn are lines of latitude located at 23.5 degrees north and south of the Equator, respectively, marking the most northerly and southerly points where the Sun can be directly overhead.