What is the name of the 0° latitude line circling Earth?

The Equator is the 0° latitude line circling Earth.

It divides the planet into the Northern Hemisphere and Southern Hemisphere and forms a great circle around Earth. The Equator passes through South America, Africa and maritime Southeast Asia, crossing countries such as Ecuador, Brazil, Kenya, Indonesia and Kiribati.

Places near the Equator generally experience little seasonal change in daylight length, although local climates vary greatly with altitude, rainfall and distance from the ocean. Earth’s rotation produces a slight bulge around the Equator, so the planet’s equatorial diameter is larger than its polar diameter. The Equator is a line of latitude, not longitude. The Prime Meridian is the 0° longitude line and passes through Greenwich, England; confusing these two reference lines is a common mistake.