A guardianship is a fiduciary relationship by which one person, the guardian, acts for another, the ward, who is regarded as being incapable of managing his or her own affairs. Statutes in every state provide for the appointment of a guardian of a person and the estate of a minor. These statutes also provide for the appointment of a guardian for someone who has been declared by a court to be non compos mentis, i.e., not of sound mind, memory, or understanding. Many states have statutes that provide for the appointment of a conservator for a person, who, because of physical or mental infirmity or age, is unable to handle his/her affairs, but who has not been declared non compos mentis.
In most jurisdictions, the father and mother are joint natural guardians of their minor children, and there is no need for a guardianship unless both parents die before a minor reaches the legal age of majority. The age of majority is the legally defined age at which a person is considered an adult, with all the rights and responsibilities of adulthood. The age of majority is defined by state laws, which vary by state, but is 18 in most states.