Questionnaire
A Questionnaire is a versioned, FHIR-inspired form: a tree of questions answered about a patient or an encounter. You touch it whenever you define a data-collection form, render one for filling, or submit answers — which can flow back out as Observations. It captures both clinical data and arbitrary non-clinical structured data.
Questionnaire Response Template
A QuestionnaireResponseTemplate is a clinician's saved "favourite" or order set: a reusable, shareable bundle that pre-fills a questionnaire response along with its medication requests and activity definitions. Reach for it when building authoring shortcuts that seed several clinical resources from one named template.
Value Set
A ValueSet is a FHIR-aligned composition of coded concepts drawn from one or more code systems. Reach for one when a questionnaire needs to constrain a coded answer to a fixed set of options.
Observation Definition
An ObservationDefinition is master data describing how a particular observation is captured — its code, permitted data type, unit, method, body site, and (interpretation) reference ranges. You create one when you need a measurement collected consistently across forms; questionnaires reference it so the same observation (blood pressure, say) is recorded the same way everywhere, whether instance-wide or within a single facility. One observation code can back several definitions. The model loosely follows the FHIR ObservationDefinition resource.
Specimen Definition
A SpecimenDefinition is a reusable, facility-scoped template for a kind of specimen: what material to collect, how to prepare the patient, how to collect it, and how it's held in a container for testing. A lab maintains a repository of these, and an Activity Definition or Service Request references one so the same container and handling rules apply every time. When a concrete Specimen is instantiated from a definition, the link is kept and the specimen copies the definition's data for history and integrity.
Activity Definition
An ActivityDefinition is a FHIR-aligned, facility-scoped template for a clinical activity. It stores the defaults needed to spin up a downstream resource — currently a Service Request — and you "apply" it against an encounter, which merges those defaults with the encounter context to produce the live resource.
Charge Item Definition
A charge item definition is a facility's pricing template for a billable resource: it answers "how much does resource X cost". It binds the resource to a set of price components — base rate, surcharges, discounts, and taxes — that get evaluated when a charge item is generated during data entry. You touch it when defining or revising the prices a facility charges.
Product Knowledge
ProductKnowledge is the reusable definition of a product — its coding, base presentation unit, ingredients and nutrients, drug characteristics, and storage rules. Define it once and every concrete Product points back to it instead of carrying duplicate data. A definition is either instance-wide or scoped to a single facility.