A more thorough explanation:

A putative father is a man who is believed to be the biological father of a child, but his paternity has not been legally established.

For example, if a woman has a child and is not married, the man she claims is the father may be considered a putative father until a DNA test or legal paternity determination is made.

Putative fathers may have limited legal rights and responsibilities until their paternity is established. This can include visitation rights, child support obligations, and the ability to make decisions about the child's upbringing.