A more thorough explanation:

A state's ward is a person who is under the protection or care of the government. This can include minors who have been assigned a permanent guardian by a juvenile court, or those who are under the supervision of a juvenile court but still have their parental rights intact.

For example, a child who has been removed from their home due to abuse or neglect may become a state's ward and be placed in foster care or with a permanent guardian. Similarly, a teenager who has been in trouble with the law may be placed under the supervision of a juvenile court and become a temporary ward of the state.

The term "ward" can also refer to a territorial division in a city for the purposes of city government, or to the act of guarding or protecting something or someone. In the past, it was used to refer to a person who guards something, such as a castle guard.