An equatorial mount is a tool that helps people look at space stuff like stars and planets. It's like a big tripod with a special attachment that helps it move in the same way the Earth moves.
You see, the Earth is always spinning around its axis, which is like an imaginary line going through the North and South Poles. As it spins, it also moves around the sun. This movement is called rotation and revolution.
The special attachment on the equatorial mount makes it move in the same direction as the Earth's rotation. This makes it easier to track objects in the sky as they appear to move from east to west.
Just imagine playing a game of tag with friends. If you were standing and spinning around in circles, it would be really hard to tag them because you'd be moving in all different directions. But if you were all spinning in the same direction around a circle, it would be much easier to tag them because you'd all be moving in the same way.
That's kind of how an equatorial mount works. It helps people see space stuff better and track objects in the sky by moving in the same direction as the Earth.