Polish coins and banknotes are money that people in Poland use to buy things. Coins are round and made of metal, and there are different sizes and denominations. The bigger the coin, the more it's worth. Banknotes are pieces of paper that have numbers and pictures on them, and they also come in different amounts.
For example, there is a 1 Grosz coin which is the smallest denomination and not worth much, a 2 Grosz coin which is a little bigger and worth a little more, and a 5 Grosz coin which is bigger than the 2 Grosz and worth even more than the 2 Grosz.
There are also banknotes with different values, like the 10 Zloty banknote which has a picture of a famous Polish writer, or the 50 Zloty banknote which has a picture of a famous Polish astronomer.
People use these coins and banknotes to buy things at stores, like toys, candy, and clothes. They can also use them to pay for services, like going to the movies or getting a haircut.
When you have some coins and banknotes, you also need to take care of them. You should keep them in a safe place so you don't lose them. And if you want to trade them for something else, you can go to a bank where they can help you exchange them for another currency or for more coins and banknotes.