It's called "zero longitude". If you mark a dot on your globe at a few hundred
points that all have zero longitude, they form a line between the north and
south poles that passes through Greenwich, UK, called the "Prime Meridian".
0 degrees
0 degrees longitude, which runs through Greenwich is called the "prime meridian."
0 degree longitude is is called the Prime Meridian.
longitude.
0 degrees longitude
The prime meridian is a line at 0 degrees longitude.
The prime meridian is located at 0 degrees longitude.
prime meridian
The Equator is 0 degrees latitude, and the Prime (or Grenwich) Meridian is 0 degrees longitude.
longitude
Another name is Prime Meridian.
The intersection of 0 degrees latitude and 0 degrees longitude is known as the Prime Meridian and the Equator.