HL7 is one of several American National Standards Institute (ANSI) - accredited Standards Developing Organizations (SDOs) operating in the healthcare arena.
Hospitals and other healthcare provider organizations typically have many different computer systems used for everything from billing records to patient tracking. All of these systems should communicate with each other (or "interface") when they receive new information but not all do so. HL7 specifies a number of flexible standards, guidelines, and methodologies by which various healthcare systems can do this.
Patient Administration (ADT), Order Entry and Results Reporting are the most often implemented messages of the HL7 standard.
Apart from this HL7 also addresses the following healthcare domains such as: