Family is a term that has been defined in a variety of ways, with diverse discourses depending on the respective discipline or field. In general, the family is viewed and discussed from the perspectives of structure, function, roles, forces, relationships, systems, culture and ethnography.
Sociologist E. W. Burgess has identified the following characteristics of the family: (1) united by marriage, blood, or adoption; (2) recognized as one's own household, regardless of cohabitation or separation; (3) interaction among family members who assume intrafamily roles; and (4) a unique family culture. However, in the modern family, there are a variety of family images that cannot be captured by these characteristics.
Family nurse practitioner M.M. Friedman (M.M. Friedman) has argued that families are emotionally involved with each other, physically close to each other, andlivingFamily nurse practitioner S.M. Harmon Hanson and others have defined a family as two or more people who depend on each other for emotional, physical, and financial support.
In family health care nursing, the family is considered to be both the caretaker of the sick patient and an organism that can itself be the object of assistance, and nursing developments unique to the family health care nursing perspective have been accumulated, such as the development of family assessment and nursing intervention for the family.

References
(1) Marilyn M. Friedman (Author) / Sayumi Nojima (Supervisor): Family Nursing Theory and Assessment, HERUSU PUBLISHING ,1993.
2) Shirley May Harmon Hanson, Sheryl Thalman Boyd (Author) / Keiko Murata, Noriko Tsuda, Yasuko Arakawa (Translators): Family Health Nursing Theory, Practice and Research, Igaku Shoin, 2001.
(3) Kazuko Suzuki, Yuko Watanabe (eds.): Family Nursing Theory and Practice, 3rd edition, Japan Nurses Association Press, 2006.
(4) Sayumi Nojima (supervisor), Ayami Nakano (ed.): Nursing Practice to Bring Family Empowerment, HERUSU SHUPPAN, 2005.