Any "straight" line between the north and south poles is a meridian.
(It can't actually be "straight" because it's on the surface of a sphere. But we
describe it that way to mean that it's a line that just goes on about its business
from one pole to the other by the shortest route, without any squiggles, waves,
breaks, or extra curves in it.)
the difference from the prime meridian
By a W for West
The opposite side of the globe from the Prime Meridian is called the International Date Line. It is located 180 degrees away from the Prime Meridian and serves as the marker where each new day begins.
That meridian has no special name. If it's shown at all on a map or globe, it'll be labeled "60".
It goes from the top of the globe to the bottom from about the Atlantic Ocean.
Meridian.
No meridian is a great circle. Each meridian is a semi-circle, extending between the poles.
The Prime Meridian
The equator divides the globe into northern and southern hemispheres.The prime meridian divides the globe into eastern and western hemispheres.Note: All six of the aforementioned items are imaginary.
A. at zero degress
the prime meridian(:
the difference from the prime meridian
On the globe it is the last country south of the Greenwich Meridian
the difference from the prime meridian
The 180th Meridian is often referred to as the Antimeridian. It is exactly halfway aroung the globe for the Prime Meridian, which is 0 degrees, and occurs at Greenwich, England.
Zero degrees ! The Prime Meridian is the starting point for the angular divisions around the globe.
The International Date Line.