Okay kiddo, so pea soup is a kind of soup that is made with a vegetable called peas. You know those little green round things that sometimes you have on your plate? Yes, those are the same ones!
So, first people start by cooking the peas in water until they become really soft. Then, they blend the peas until they become a smooth, thick liquid.
After that, they add some other yummy things like salt, garlic, onions, and sometimes ham or bacon, to give it more flavor. Then they cook it all together until it becomes a nice hot soup that you can eat with a spoon.
Some people like to eat their pea soup with some bread or crackers, but you can eat it however you like! And that's pretty much it, pea soup is a tasty soup made with cooked peas and other tasty things.