Grandparents are the father or mother of a person's own father or mother, being respectively a grandfather (also colloquially grandpa, grandad, gramps, pop or many other terms) and a grandmother (also grandma, granny, grandmama, grandmums, gran, nana or many other terms). Everyone has a maximum of four genetic grandparents, eight genetic great-grandparents, sixteen genetic great-great-grandparents, etc. Sometimes these numbers are lower and in the case of having only two or three grandparents sibling or half-sibling incest would be incorporated.

In cases where the parents are unwilling or unable to provide adequate care for their children, in cases of death or other, grandparents often take on the role of primary caregivers. Even when this is not the case, grandparents often participate in the raising of children.

In traditional cultures, grandparents often had a direct and clear role in relation to the care and nurture of children.

One can also be a step-grandparent. A step-grandparent can be your parent's stepparent or your stepparent's parent. A stepparent's stepparent is called a step-step-grandparent, etc.Fact: date=May 2008

The various words for grandparents at times may also be used to refer to any elderly person, especially the terms gramps, granny, grandfather, grandmother and even more types that most families make up themselves.

Two individuals who have grandparents in common, but are not siblings, are called first cousins. The parents of a person's first cousins are his or her uncles and aunts.

Titles

In writing, grandfather and grandmother are most common. In speech, grandpa and grandma are most common in the US, where grandfather/-mother is very rare when referring to a grandparent in person. In Britain and New England nan, nana, nanny and other variations are often used for grandmother in both writing and speech.

Numerous other variants exist, such as gramp and grandpap or pop for grandfather and grandmom, grandmama and grammy for grandmother, etc.

Given that people may have two living sets of grandparents, some confusion arises from calling two people "grandpa" or "grandma", so often two of the other terms listed above are used for one set of grandparents. Another common solution is to call grandparents by their first names ("Grandpa George", "Grandma Anne", etc.) or by their family names ("Grandpa Jones", "Grandma Smith"). In America (where most families are of mixed ethnicity), many families call one set of grandparents by their ethnic names (i.e., Hispanic grandparents might be called "Abuelo" and "Abuela", French grandparents might be called "Pépé" and "Mémé", or Dutch and German grandparents might be called "Opa" and "Oma" ). As you can see, there are many different types of names for "grandma" and "grandpa" for different languages and cultures.