When a child is adopted, do you just assume that the parental rights of the first parent have been terminated? Not so fast. There are a number of situations in which this may not be the case.
For example, a stepparent adoption is often used when the person who married into the family wants to be more than just a new adult living in the home. That person loves their partner's child from an earlier relationship and wants to make the new relationship official, along with all of the rights and responsibilities that go with it. This doesn't happen with every stepparent, as it is possible to marry without officially adopting the kids. Stepparent adoptions are a quick way to expand the new parent's rights without taking them away from the biological parent.
A "second parent adoption" is very similar, giving that second parent new rights regarding the kids. Both parents are granted legal authority. Experts note that same-sex couples will often go this route.
As you can see, it's common for an adoption to simply expand legal rights that adults have, rather than transferring those rights from one person to another. This is done for many reasons, such as increasing the bond between a child and a stepparent, ensuring that the stepparent has legal rights in an emergency and ensuring a smooth transfer of assets upon a parent's passing.
However, these are just two examples of different types of adoptions. It's very important for those who are considering adoption to know about all of the options they have and what legal steps to take.
Source: Family Equality Council, "Issues: Adoption and Foster Care," accessed Sep. 08, 2017