What is the difference between HL7v2 and HL7 FHIR?

HL7v2 is a pipe-delimited messaging standard from the 1980s that transmits clinical events (admissions, results, orders) between systems via point-to-point messages. FHIR is a modern API-based standard using RESTful web services for on-demand, granular data retrieval. HL7v2 excels at event notification but is poorly suited to modern data retrieval; FHIR enables real-time integration and is the strategic direction for NHS interoperability.