Glossary

Aggregation

A strong form of an association. The relationship between a system and the components that make up the system can be called an aggregation, for example. An aggregation is expressed as a Qualifier on the association class. Aggregation often implies, but does not require, that the aggregated objects have mutual dependencies.

Association

A class that expresses the relationship between two other classes. The relationship is established by the presence of two or more references in the association class pointing to the related classes.

Cardinality

A relationship between two classes that allows more than one object to be related to a single object. For example, Microsoft Office is made up of the software elements Word, Excel, Access, and PowerPoint.

CIM

Common Information Model is the schema of the overall managed environment. It is divided into a Core schema, Common schemas and extended schemas.

CIM schema

The schema representing the Core and Common models. Versions of this schema will become available as the schema evolves.

Class

A collection of instances, all of which support a common a type, that is, a set of properties and methods. The common properties and methods are defined as features of the class. For example, the class called Modem represents all the modems present in a system.

Common model

A collection of models specific to a particular area, derived from the Core model. Included are the system model, the application model, the network model and the device model.

Core model

A subset of CIM, not specific to any platform. The Core model is set of classes and associations that establish a conceptual framework for the schema of the rest of the managed environment. Systems, applications, networks and related information are modeled as extensions to the Core model.

DMTF

Desktop Management Task Force

Domain

A virtual room for object names that establishes the range in which the names of objects are unique.

Explicit Qualifier

A qualifier defined separately from the definition of a class, property or other schema element (see implicit qualifier). Explicit qualifier names must be unique across the entire schema. Implicit qualifier names must be unique within the defining schema element – that is a given schema element may not have two qualifiers with the same name.

Extended schema

A platform specific schema derived from the Common schema. An example is the Win32 schema.

Feature

A property or method belonging to a class.

Flavor

Part of a qualifier spcification indicating overriding and inheritance rules. For example the qualifier KEY has Flavor(NoOverrideToSubclass) meaning that every subclass must inherit it and cannot override it.

GDMO

Guidelines for the Definition of Managed Objects, ISO/IEC 10165 Part 4, 1992; equivalent to ITU X.722.

Implicit Qualifier

A qualifier defined as a part of the definition of a class, property or other schema element (see explicit qualifier).

Indication

A type of class usually created as a by-product of the occurrence of a trigger.

Inheritance

A relationship between two classes in which all the members of the subclass are required to be members of the superclass. Any member of the subclass must also support any method or property supported by the superclass. For example, Modem is a subclass of Device.

Instance

A unit of data. An instance is a set of property values that can be uniquely identified by a key.

Key

A value used to identify an object within the scope of a namespace. For example, a drive letter in the scope of a system. A property that is a key will have the Qualifier KEY set to "true".

Managed object

The actual item in the system environment that is accessed by the provider. For example, a Network Interface Card.

Metamodel

A set of classes, associations and properties that expresses the types of things that can be defined in a Schema. For example, the metamodel includes a class called property which defines the properties known to the system, a class called method which defines the methods known to the system, and a class called class which defines the classes known to the system.

Metaschema

The schema of the metamodel.

Method

A Method is a declaration of a signature, that is, the method name, return type and parameters, and in the case of a concrete class may imply an implementation.

MIF

Management Information File

Model

A set of classes, properties and associations that allow the expression of information about some specific domain. For example, a Network may consist of Network Devices and Logical Networks. The Network Devices may have attachment associations to each other, and may have member associations to Logical Networks.

Model path

A reference to an object within a namespace.

MOF

Managed Object Format

Name

Combination of a Namespace path and a Model path that identifies a unique object.

Namespace

An object that defines a scope within which object keys must be unique.

Namespath path

A reference to a namespace within an implementation that is capable of hosting CIM objects.

Polymorphism

A subclass may redefine the implementation of a method or property inherited from its superclass. The property or method is thereby redefined even if the superclass is used to access the object. For example, Device may define status as a string, and may return the values "connected", "on" or "off". The Modem subclass of Device may redefine (override) status by returning "on", "off", but not connected. If all Devices are enumerated, any Device that happens to be a modem will not return the value "connected" for the status property.

Property

A value used to characterize an instance of a class. For example, a Device may have a property called status.

Provider

An executable that can return or set information about a given managed object.

Qualifier

A value used to characterize a method, property, or class in the metaschema. For example, if a property has the qualifier KEY with the value "true", the property is a key for the class.

Reference

References are special property types that are references or "pointers" to other instances.

Schema

A namespace and unit of ownership for a set of classes. Schemas may come in forms such as a text file, information in a repository, or diagrams in a CASE tool.

Scope

Part of a Qualifier specification indicating which metaconstructs the Qualifier can be used with. For Example the Qualifier ABSTRACT has Scope(Class Association Indication) meaning that it can only be used with Classes, Associations, and Indications.

Scoping object

Objects which represent a real-world managed element, which in turn propagate keys to other objects.

Signature

The return type and parameters supported by a method.

SMI

Structure of Management Information, IETF RFC 1155

SNMP

Simple Network Management Protocol, IETF RFC 1157

SQL

Structured Query Language. The International Standard for the Database Language SQL is ISO/IEC 9075: 1992.

Subclass

See Inheritance.

Superclass

See Inheritance.

Top level object

A class or object that has no scoping object.

Trigger

A trigger is the occurrence of some action such as the creation, modification or deletion of an object, access to an object or modification or access to a property. Triggers may also be fired as a result of the passage of a specified period of time. A trigger typically results in an Indication.

UML

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