There are four basic degrees of consanguinity:
First degree: siblings, who share the same parents
Second degree: first cousins, who share the same grandparents
Third degree: second cousins, who share the same great grandparents
Fourth degree: third cousins, who share the same great, great grandparents
To learn more please see this article at The Island Register.
and Lucie Consentino's article on consanguinity at her website, Acadian & French Canadian Ancestral Home