Family resemblance refers to Wittgenstein's contention that a category does not have a defining feature/essence that must be shared by all members of the category. Rather, there is a set of features distributed among members of a category, with no single feature essential for inclusion in the category. Family resemblance is defined, likewise, as a structure of categories in which each member shares different features with different members. Few, if any, features are shared by every single member of the category.