Imagine that the Earth is like a big balloon filled with air. The air inside the balloon is held in place by the balloon itself, just like how the atmosphere around the Earth is held in place by gravity.
Now, plants and trees are like straws on this balloon. They suck up water from the ground and release it into the air as vapor through a process called transpiration. This creates a kind of "suction" effect that draws in more air from surrounding areas.
The more plants and trees there are, the bigger the "straws" and the stronger the suction. This is where the biotic pump comes in. It's a theory that suggests that this natural suction caused by plants and trees helps to draw in moisture from oceans and other areas, and creates rainfall in regions that might not otherwise get as much water.
So, basically, the biotic pump is like a giant natural vacuum cleaner powered by plants and trees that pulls in moisture and helps create rain. It's a pretty cool way that nature works together to keep our planet healthy!