Expenses are the things that your family spends money on. When you go to the store and buy toys, clothes or food, that costs money and it's an expense.
Sometimes your family also has to pay for things like electricity, rent or mortgage, and water bills. These are also expenses because your family needs to use these things to live but they have to pay for them.
When your family spends money on expenses, it means that they have less money to spend on other things like vacations, toys or treats. So, it's important to make sure that your family is not spending more than they can afford on expenses. They need to make a plan to save money for things they want to buy and only spend money on things that they really need.