Retailing is when you go to a store and buy things like toys or clothes. It's like going to the candy store, but for all sorts of things!
Imagine you really like toys and you want to buy a new toy. Well, there are stores that sell toys, and those stores are called retailers!
The retailer buys lots of toys from the people who make the toys, and then they put them in their store for people like you to buy. They make sure the toys are arranged nicely so you can find what you want easily.
When you go into the store, you can pick out the toy you want and the retailer will let you buy it by giving them some money. The retailer will keep the toy you bought until you take it home with you.
Retailers also make sure that the store is clean and the toys are in good condition so you can be happy with your new toy.