A "lien" is a charge, burden or claim against property. The property can be seized and sold to satisfy and discharge the lien. This process is called "foreclosure."
A child support lien, once filed, is just like a mortgage on a house. If the house owner falls behind in house payments, the mortgage company can foreclose on the house. By filing a child support lien, you are, in effect, stepping into the shoes of the mortgage company. You can foreclose on anything the obligor owns unlss the property is exempt from foreclosure by law.
If you are attempting to collect child support in Alabama, Arkansas, California, Connecticut, Delaware, Florida, Georgia, Illinois, Iowa, Maine, Missouri, New Hampshire, New Jersey, New Mexico, Oklahoma, Pennsylvania, Rhode Island, South Dakota, Tennessee, Texas, Vermont, Virginia, Washington, or West Virginia, then your state is a member of the Child Support Lien Network.