What does equator mean?

On a globe of the Earth, some rainy afternoon, find every point you can that's

exactly mid-way between the north and south poles, and mark each one with

a tiny pencil-dot.

When you've made enough dots, you'll begin to realize that they all line up

around the 'middle' of the Earth, crossing Africa, the Indian Ocean, the Atlantic

and Pacific Oceans, and the upper part of South America.

If you made millions and millions of these dots, each one exactly mid-way between

the poles, they'd blend together into a solid line, and that line is the Equator.