Closed adoption is an adoption process in which the identities of one or both parties are kept confidential. In a closed adoption, the birth parents and adoptive family typically have no contact with each other, and the child does not know their biological parents. This type of adoption was popular during the 20th century when there were concerns about stigmatizing unwed mothers and preserving the anonymity of all parties involved. However, in recent years, many closed adoptions have been opened up through mutual consent between birth families and adoptive families to promote a sense of identity for the child.