Key Concepts

Following are the key concepts used in TQL

Name	Description
Project	A deployment unit, consisting of one or more Models, Model Facets and Queries.
Model	A unit of definition with structures to represent the Attributes and Actions of an entity.
ThingModel	One kind of Model. Used to represent things that interact with the application from outside the software system, such as sensors, devices and machines.
AppModel	One kind of Model. Used to represent an application logic construct.
DataModel	One kind of Model. Used to define a data structure.
ModelFacet	A reusable definition component that can be used (via "Combines") by Models. Usually contains its Attribute and Action definitions.
ThingFacet	One kind of ModelFacets. Used to define a reusable construct concerning interaction with things.
AppFacet	One kind of ModelFacets. Used to define a reusable construct concerning application logic.
Combines	A keyword used in Model definitions. Models "Combines" ModelFacets to acquire all the Attributes and Action definitions of the ModelFacets.
Attribute	A container that holds values for the Model.
Action	A definition of a process(es) associated with a Model.
Actionable Attribute	An attribute whose value changes will automatically trigger the processes defined by Action(s).
Workflow	A sequence of tasks that are orchestrated and repeatable.
Task	A unit of work.
Model Instance	An incarnation of a Model definition.
Deploy	The process of compiling Model definitions and make the post-compilation artifacts (such as model runtime) available to the running TQL Engine
Instantiation	The process of creating Model Instances from a Model definition. The process of creating workflow instances from a Workflow definition.
Query	Any operation(s) on the model instance data (or model data), which includes filtering, joining, and manipulations.
Subscription	Subscribing to a topic
Topic	Topic is a string value that model developers use to subscribe and eventually receive notifications.
/wiki/spaces/TQLDocs/pages/1179763	Custom or System defined Model definitions (Example: Primitive types - String, Number etc)
Macros	Macros help keep TQL code (portions) organized and reusable. Macros have Arguments and Result (Reusable portion of TQL code)
Protocol Handler	Protocol Handlers are communication (Channel) transport handler within A-Stack. Protocol Handlers are one of the key extension points of A-Stack
Facet Instances	Facet Instances are runtime definition of A-Stack capabilities by choosing appropriate Facet Types.
Facet Types	A-Stack capabilities are provided as Facet Types. Example, SffTqlFacet, SffMsgFacet etc
FacetID	Unique identifier given each Facet Instance definition. A-Stack adds fid- user provided Facet Instance ID
Template Processing	Template Processing provides runtime access to variable values. XPath expressions can be used with Template Processing.
Atomic Domain Languages (ADL)	Atomiton provided Domain Languages to build IoT Applications
Thing Query Language (TQL)	Thing Query Language is core part of Atomic Domain Language. TQL consists of Thing Definition Language (TDL) and Thing Interaction Language (TIL)