家庭是一种以婚姻、血缘、收养或同居等关系为基础而形成的共同生活单位由婚姻组成的家庭关系，经由生育孩童，产生出以血缘为连带的家庭成员。除此之外，家庭也可以由收养而创建的亲子关系组成。

家庭这个词还可以进一步扩展延伸至祖先辈，比如家谱中所列举的人；而横向也涵盖了姻亲关系在内的亲属；当然，也有用于没有亲戚关系的人，如，同住在一间房屋里的其他人所构成的。

因共同的生活，常常会把一家与一户混淆，一家组成一户，则会把住所内的房客和寄宿者统计在内。由于血缘，家庭也会与家族混淆，但一个家族可分为好几户。家庭常与婚姻混淆，复杂的习俗确定着家庭内同居的男男女女关系，婚姻既包含关系的创建和终止，也包含相互的义务和承诺。

In the context of human society, a family (from Latin:familia) is a group of people affiliated by consanguinity (by recognized birth), affinity (by marriage), or co-residence (as implied by the etymology of the English word "family") and/or shared consumption (see nurture kinship). Members of the immediate family includes spouses, parents, brothers, sisters, sons and/or daughters. Members of the extended family may include grandparents, aunts, uncles, cousins, nephews, nieces, and/or siblings-in-law. Sometimes these are also considered members of the immediate family, depending on an individual's specific relationship.