A more thorough explanation:

A foster child is a minor child who is placed in the care of a state-licensed adult, instead of their parent or guardian. This happens when the child's home environment is unsafe or unstable, usually due to abuse or neglect. Sometimes, parents are unable to care for their children because of illness, death, or incarceration. In rare cases, parents voluntarily give up their parental rights and place their child in foster care.

Foster children can live in different places, such as a group home, ward, or a private home with a foster family. Child welfare agents may also find relatives or adults who know the child to care for them.

Most foster children eventually go back to their parent or guardian after the problems that caused them to be removed are resolved. Others find permanent homes through adoption or permanent guardianship. However, some foster children reach the age of majority and "age out" of the foster care system before finding a permanent family.

For example, a child who has been neglected by their parents may be placed in foster care with a family who can provide a safe and stable home. Another example is a child whose parent is incarcerated and unable to care for them. In this case, the child may be placed with a relative or a foster family until their parent is released.