There's no single line of latitude called "the line that runs around the world". Every line of latitude runs around the world!

Here's what you need to know:

* Lines of Latitude: These are imaginary circles that run east-west around the Earth, parallel to the equator.

* Equator: The most famous line of latitude is the equator, which is at 0 degrees. It divides the Earth into the Northern Hemisphere and Southern Hemisphere.

* Other Lines: There are countless other lines of latitude, ranging from 1 degree to 89 degrees north or south of the equator.

Let me know if you'd like to know more about specific lines of latitude!