A submersible pump is like a magic straw that drinks water from a big cup called a well, and then spits it out somewhere else. The straw is called "submersible" because it goes underwater and sits at the bottom of the well.
When you turn on the switch, the submersible pump starts to work by sucking water in through a special part called the impeller. The impeller is like a fan with curved blades that move the water around and push it up the straw. The straw is a long, waterproof tube that carries the water up and out of the well.
Once the water reaches the top of the straw, it goes through a pipe and comes out of the pump. Submersible pumps can be used for lots of different things, like watering plants in a garden or filling up a swimming pool.
So, remember when you drink your juice box with a straw, think of a pump that can drink water from a well and give it to the plants!