Accounting is like keeping track of the money that is coming in and going out of your pocket. For example, when you buy an ice cream, you take $3 out of your pocket and give it to the ice cream shop. That's part of accounting – it's keeping track of how much money you spend and how much money you have left.
Accounting also helps companies keep track of their money. They have to make sure they are not spending too much and also make sure they are getting enough money to keep their company going and provide a good service. So they need to keep track of how much they are spending and how much they are making. That's what accounting is – keeping track of where money is coming from and where it's going.