Child support is an issue that comes up in many divorce cases, but it also comes up apart from any consideration of marriage or divorce. Child support is money that a court can order one parent (or both parents for that matter) to pay for the support of one or more of their children.
If there is a question of paternity, that would have to be dealt with first, but given that the parent-child relationship is established, factors that will affect child support decisions in California include: the income level of each parent, the amount of time each parent spends taking care of the child, and the age of the child (support ends at 18, or 19 if the child has not yet graduated from high school.)
If a child dies, marries, or joins the military, support will end. But if a child is mentally or physically disabled and cannot support him or her self as an adult, support will continue past 18. The income and expenses of each parent are submitted on an official Income and Expense Declaration form, which is filled out under penalty of perjury; and the amount owed is determined based on a pre-set formula which is itself based mostly on net disposable income.