Which statement best describes the role of resources in FHIR?

• A. They are optional extensions
• B. They are internal only
• C. They are the building blocks for representing data
• D. They are only for patient data

Answer: (C)

In FHIR, resources are the building blocks for representing data. Each resource encodes a single, discrete clinical concept—such as a Patient, an Observation, or an Encounter—in a standard structure with an id, metadata, and a defined set of elements. This standardization lets different systems understand and exchange information consistently. Resources are designed to be the unit of exchange: you can create, read, update, search, and bundle multiple resources together to convey a complete clinical scenario. They can be constrained or extended with profiles and extensions to fit local needs while preserving interoperability. They aren’t optional extensions, they aren’t restricted to internal use, and they cover far more than patient data, encompassing a wide range of healthcare information.