The term person in common usage means an individual human being. In the fields of law, philosophy, medicine, and others, the term also has specialised context-specific meanings.

In many jurisdictions, for example, a corporation is considered a legal person with standing to sue or be sued in court. In philosophy and medicine, person may mean only humans who are capable of certain kinds of thought. This could also extend to late fetuses and neonates, dependent on what level of thought is required.

Personhood in theology

Person and personhood were used in concepts in the early Christian theological tradition, during the first centuries A.D. by the Church Fathers. The very concept of person (prosopon in Greek) was the result of a theological dispute, how God, according to the Christian (Orthodox) teaching, can be One and three at the same time. Further explication of the problem led to the formulation that there is one substance (or being) and three subsistences (hypostases): God Father, God Son and God Holy Spirit, but still just one God, not three. This theological concept of the person as something that has a specific identity and holds the fullness of being, was applied to the human being as well. The Church Fathers interpreted the "icon of God" in man as human ability to exist as a person, having his/her own unique identity in communion with other persons. Later in the West the concept was translated into Latin as persona and was explained by Boethius and St. Augustine as something characterized by rational capacities.

Scientific approach

As an application of Social Psychology. and other disciplines, phenomena such as the perception and attribution of personhood have been scientifically studied. Typical questions addressed in Social Psychology are the accuracy of attribution, processes of perception and the formation of bias. Various other scientific/medical disciplines address the myriad of issues in the development of personality.

Individual rights and responsibility

Closely related to the debate on the definition of personhood is the relationship between persons', individual rights, and ethical responsibility. Many philosophers would agree that all and only people are expected to be ethically responsible, and that all people deserve a varying degree of individual rightsFact: date=March 2009. There is less consensus on whether only people deserve individual rights and whether people deserve greater individual rights than non-peopleFact: date=March 2009. The rights of animals are an example of contention on this issue.

Who is a person?

• Human beings - In contemporary global thought, once human beings are born, personhood is considered automatic.
• Exceptions: - Exceptions to this are often emotive and controversial. Some people have given opinions that fetuses, the disabled, the profoundly and long term brain damaged, those in coma or other persistent vegetative states, may be dubious as regards personhood. Such views are strongly debated from both sides. Historically, personhood has been denied to women, perceived other races, the mentally disabled, and in many tribal societies, all people not from the tribe.
• Animals - Some philosophers and those involved in animal welfare, ethology, animal rights and related subjects, consider that certain animals should also be granted personhood. Commonly named species in this context include the Great Apes and possibly cetaceans or elephants, due to the acknowledged intelligence and intricate societies of such species. In animistic religion, animals, plants, and other entities may be persons or deities.
• Certain societal constructs - certain social entities, are considered legally as persons, for example some corporations and other legal entities. This is known as legal, or corporate, personhood.