Terms Used in EDMassist

The following terms are used throughout the EDMassist

Term	Description
Application data	A data item with values that provide information of interest to application software referencing it.
Complex entities	A complex entity denotes an implicitly or explicitly declared entity data type that is part of a supertype and subtype network.
Data	A computational unit with its content representing a piece of information.
Data type	An identifier denoting the class to which a data belongs.
Database	A concrete realization of a repository by means of a database engine, such as EDMdatabase
Dictionary data	A data item with values representing information about the structure and behavior of another data instance.
Entity	An entity denotes something that exists in the real world and information about it is of interest to its viewer.
ENTITY data type	An EXPRESS language construct that is used to describe structures of a data type in terms of attributes and local rules.
ENTITY instance	An instance of the EXPRESS ENTITY data type that exist in a database.
EXPRESS	The formal name of a data definition language. It is used to describe the information requirement of a domain such as STEP Application Protocols, Generic Resources and some aspects of Implementation Methods. A description of the EXPRESS language is set out in Part 11 of STEP (ISO 10303-11).
Global rule	An EXPRESS language construct using the keyword RULE to define constraint that applies to one or more instances of an ENTITY Data type or ENTITY Data types.
Information	An abstract thing providing knowledge (facts, concepts, instructions etc.) about an entity.
Language binding	A specification of the SDAI in a particular programming language.
Local rule	A class of EXPRESS RULE construct used to define the uniqueness and domain constraint of the EXPRESS ENTITY data type.
Model	A virtual container within which related data items exists.
Repository	A logical data storage that is identifiable by name alone.
Schema	An EXPRESS language construct, which is used to denote a collection of related data types.
Session	The period when the facilities of the EXPRESS Data Manager are active for a client.
TYPE data type	An EXPRESS Language construct that is used to create defined data types and declares an identifier to refer to it.