Child support agency Australia is like a big group of people who help families when they can't agree on how to take care of their kids.
Let's imagine your parents are divorced or separated, and your mom takes care of you most of the time. Your dad wants to help take care of you too, but he doesn't live with you anymore.
This is where the child support agency comes in. They help your dad give money to your mom to help take care of you. This money is called child support.
The child support agency makes sure that your dad gives the right amount of money to your mom based on how much he can afford and how much it costs to take care of you.
They also make sure that your dad pays on time every month so that your mom can count on the money to help take care of you. This is important because kids need a lot of things like food, clothes, and sometimes even medical care.
So, the child support agency is like a big helper that makes sure your parents work together to take care of you even if they don't live together anymore.