I found this chart created by Alice J. Ramsay in 1987 that explains our relationship to our family members.  

There are also additional terms such as "Double cousin", "Half-cousin", "Stepcousin", etc, explained on the article.

Term Definition Example Chart
Double cousin Double cousins arise when two siblings of one family mate with two siblings of another family. The resulting children are related to each other through both of their parents and are thus doubly related. Double first cousins share both sets of grandparents and have twice the degree of consanguinity of ordinary first cousins; genetically, they are as related as half-siblings. In a scenario where two monozygotic (identical) twins mate with another pair of monozygotic twins, the resulting double cousins would test as genetically similar as brothers or sisters. Double second cousins can arise in two ways: from the relationships of two first-cousins with two other first-cousins or from the relationships two double-first-cousins with two other persons. May also be known as 'Cousins on both sides.' Joseph and Julie are double first cousins because each is related through their mother's family and also their father's family, the result of a brother and sister (Helen and Eugene) having married another brother and sister (James and Mary). For Joseph and Julie, each has a mother who is an aunt by blood of the other and a father who is an uncle by blood of the other.
Gary Glenda
Jason Beatrice
James Helen Eugene Mary
Joseph Julie
Half-cousin Half-cousins are the children of two half-siblings, and their respective spouses. Joseph and Lilian are half cousins because their parents (Helen and Charles) are half-siblings, their grandmother (Beatrice) having remarried.
Jason Beatrice Anthony
James Helen Charles Janet
Joseph Lilian
Stepcousin Stepcousins are either stepchildren of an individual's aunt or uncle or nieces and nephews of one's stepparent. Joseph and Rachel are stepcousins because Joseph's uncle (Eugene) has become Rachel's stepfather as a result of Rachel's mother (Corinda) having remarried Eugene.
Jason Beatrice
James Helen Eugene Corinda Colin
Joseph Rachel
Cousin-in-law A cousin-in-law is the spouse of an individual's cousin or the cousin of one's spouse. Joseph and Roger are first cousins-in-law to each other because Roger's wife (Julie) is Joseph's first cousin.
Jason Beatrice
James Helen Eugene Mary
Joseph Julie Roger
Maternal or paternal cousin A term that specifies whether one individual is a cousin of another through the mother's side of the family (maternal) or the father's side (paternal). If the relationship is not equally paternal for both or equally maternal for both, then the paternal cousin of one is the maternal cousin of the other. Julie and Natalia are maternal first cousins (being related through their mothers). Julie is also Joseph's maternal first cousin (as related on Joseph's mother's side), but Joseph is Julie's paternal first cousin (as related on Julie's fathers's side). Joseph and Natalia would only be related if they shared a common ancestor.
Jason Beatrice Gary Glenda
James Helen Eugene Mary Maud Mark
Joseph Julie Natalia

I found the following genetic relationship chart that was fascinating on the International Society of Genetic Genealogy Wiki.  It shows the average amount of autosomal DNA inherited by all close relations up to the third cousin level.

©June 2021 by hisiamone