The term affinity refers to a familial relationship formed through marriage, as opposed to a blood relationship.

Affinity is often used to describe the relationships between a person and their spouse's relatives. It's a legal and genealogical concept that helps determine Inheritance rights, legal obligations, and other matters related to family connections.

If someone passes away and their Estate goes through the Probate process, "affinity relationships" might become relevant when determining who inherits the deceased’s Assets if no valid Last Will and Testament was created prior to the death.

Affinity relationships are distinct from Consanguinity, which refers to relationships based on blood or descent.

Laws regarding affinity vary by state, so it's best to consult with an Estate Attorney or Probate Attorney to fully understand how affinity relationships are recognized and applied when Administering an Estate.