The difference between Cousin and First cousin

Cousin as a noun:

The child of a person's uncle or aunt; a first cousin.

Cousin as a noun:

Any relation who is not a direct ancestor or descendant but part of one's extended family; one more distantly related than an uncle, aunt, granduncle, grandaunt, nephew, niece, grandnephew, grandniece, etc.

Cousin as a noun (obsolete):

Cousin as a noun (figurative):

Something kindred or related to another.

First cousin as a noun:

A child of a parent's sibling; a nephew or niece of a parent; a child of one's uncle or aunt.

First cousin as a noun:

A person who shares common grandparents but not common parents.