A child is brought into the child welfare (foster care) system when, for one reason or many, their family system fails. A child in foster care is in need of shelter and support, and if no relatives can provide a suitable home, child welfare must provide one. While this home may turn out to be an institution, more often a child is taken into pre-approved private residences with trained foster parents.
Once in a foster home, a foster child must learn to adapt to the new environment. Many of these children have been traumatized to some point, and have experienced things no child should. Some have serious issues trusting adults, so accepting and trusting strangers, aka foster parents, can be very difficult for them.
If the foster home is just a temporary situation to meet an emergency need, a child will again have to adjust to whatever environment they are moved to next. All of this can add up to lifelong emotional and psychological problems.
What will happen to these children? In some cases, they will eventually be returned to their birth families, with varying outcomes, some successful, some not. Others will remain in the foster care system for the rest of their childhood. Still others may find permanent adoptive homes, sometimes with their foster parents, sometimes with families wishing to expand.
The most crucial thing a foster child needs to overcome the hurdles of their childhood is a safe and secure environment, with adults who are able to provide understanding and affection. Without it, a child can be lost.