The term 'placement' is used to define when a child enters a different living situation other than the birth home. It is used both in adoption and foster care situations. It is common to hear about a family taking their first foster placement or how a child entered a home as an adoptive placement.
Placement in a foster or adoptive home usually means that the foster or adoptive parents have signed official placement papers, which detail the expectations of the foster or adoptive parents as well as the agreed upon subsidy amount. These documents will vary by state and by placement needs.