Explicit
Clear and voluntary indication of preference or choice, usually oral or written
Implicit(Implied consent)
Inferred from the words or behavior of the patient, or surrounding circumstances such that a reasonable person would believe that consent has been given, even though no direct, explicit and unequivocal words of agreement have been given
Informed consent
Must be voluntary, Must have mental capacity, Must be informed of foreseeable implications of consenting to treatment or the possible impacts of refusing