It is an application of information technology to healthcare.
It is the:
"understanding, skills and tools that enable the sharing and use of information to deliver healthcare and promote health" (British Medical Informatics Society).
It also forms part of the wider domain of eHealth. These later-generation terms reflect the substantive contribution of the citizen & non-medical professions to the generation and usage of healthcare data and related information. Additionally, medical informaticians are active in bioinformatics and other fields not strictly defined as health care.
