A second cousin is a relative who shares the same great-grandparents with you but does not share the same grandparents. In other words, your second cousin is the child of your parent's cousin. Both you and your second cousin are the great-grandchildren of the same couple, but you descend from different grandchildren of those great-grandparents

. To clarify the relationship:

• Your first cousins share grandparents with you.
• Your second cousins share great-grandparents with you.
• The parents of second cousins are first cousins to each other.

For example, if your father's cousin has a child, that child is your second cousin

. Second cousins are generally considered more distantly related than first cousins and share about 3.125% of their DNA on average

. Additionally, the term "once removed" applies when there is a generational difference. For instance, your second cousin's child would be your second cousin once removed

. In summary, second cousins are people who share the same great-grandparents but have different grandparents, making them the children of your parent's cousins