Familiar vs. pariente

The Spanish words 'familiar' and 'pariente' are often used interchangeably to refer to a family member or relative. However, there are subtle differences in their usage.

Familiar

'Familiar' is a broad term that can refer to immediate family members (like parents, siblings, etc.) and also close relatives. It generally refers to people with whom one shares a household.
Me gusta hacer regalos a mis familiares y amigos.
(I like to give gifts to my family and friends.)
Sus familiares estaban convencidos de su inocencia.
(His relatives were convinced of his innocence.)
Entre familiares y gente conocida, se usa el nombre de pila.
(People use their first name when with relatives and acquaintances.)

Pariente

'Pariente' specifically refers to blood relatives or relatives by marriage. While it can also apply to immediate family members, it often more commonly refers to extended family, like cousins, aunts and uncles.
Mis primos son parientes cercanos.
(My cousins are close relatives.)
Mi suegra es una pariente por matrimonio.
(My mother-in-law is a relative by marriage.)
Voy a visitar a mis parientes en el campo este fin de semana.
(I am going to visit my relatives in the countryside this weekend.)

Summary

In summary, while both 'familiar' and 'pariente' can be used to refer to family members or relatives, 'familiar' tends to refer more broadly and inclusively to anyone within a shared household or close familial relationship. On the other hand, 'pariente' typically has narrower use, often referring more specifically to blood relatives or relatives by marriage.