Child support refers to a payment made towards the cost of caring for a minor child.
The parent that pays child support is called the non-custodial parent. In some cases, the person that receives payments is the child's custodial parent. Other times, payments are made to the state of Illinois (learn more).
A child support order is a legally-binding document that requires a parent to pay a certain amount in child support on a regular basis. There are other ways to make valid child support payments without an order, such as through a check or money order with "child support" in the memo.