There are basically two different types of adoption: closed adoption and open adoption.
In a closed adoption, there is no exchange of identifying information. Medical history of the birth parents (limited to information available at time of placement) is given to the adoptive family, and there is no other contact between the adoptive family, adoptee, or birth parents. An advantage of closed adoption is that the confidentiality of the birth parents is maintained, unless both parties choose to sign up for an adoption registry, which is a database that reunites birth parents and adoptees.
Conversely, open adoption signifies openness between the birth parents and the adoptive parents. Open adoption allows for birth parents to have more information about their child. The amount of information exchanged and the contact between all parties involved is agreed upon in the adoption plan. Openness can vary between basic information exchanged, to the sending of letters and pictures, to face-to-face visits. Today, most adoptions in the United States are open, and birth parents can choose the adoptive family by previewing their profiles. Additionally, adopted children have the opportunity to know information about the birth parents who placed them.