In spain, a name usually has three parts: the first name, the father's last name, and the mother's last name.
The father's last name is used from one generation to the next.
The mother's last name goes only to the one generation-to her sons and daughters.
Traditionally, parent give their children the grandparent's first names.
They name the first boy after the father's fater.
They name the first girl after the father's mother.
Parent name the second boy after the mother's father and the second girl after the mother's mother.
The child's name tells the family history.