In Windows Management Instrumentation (WMI), a class from which you cannot create an instance because it does not have a full implementation. An abstract class serves as a base class from which other classes can inherit properties and methods. Also see concrete class.
A WMI base class used only as a template for derived classes. For example, the __Event system class is an abstract class. Real-world events are modeled using classes derived from the __Event class, and instances are created from the __Event subclasses.
A class that contains one or more abstract methods, and therefore can never be instantiated. Abstract classes are defined so that other classes can extend them and make them concrete by implementing the abstract methods.
A class that can not be directly instantiated. Contrast with concrete class.
A SOM class that is not designed to be instantiated, but serves as a base class for the definition of subclasses. Regardless of whether an abstract class inherits instance data and methods from parent classes, it will always introduce methods that must be overridden in a subclass, in order to produce a class whose objects are semantically valid.
(1) A class with at least one pure virtual function that is used as a base class for other classes. The abstract class represents a concept; classes derived from it represent implementations of the concept. You cannot construct an object of an abstract class. See reference class. Contrast with concrete class. (2) A class that allows polymorphism.
An abstract class is a class that you create as a basis for other classes rather than with the intention of instantiating and using. An abstract class is generally a class that is used to group a set of subclasses with a common interface. In a true OO programming language, it is not possible to instantiate an abstract class.
A class that would never instantiate an object itself, but serves as good logical building point for other classes that do instantiate themselves (concrete classes). Abstract classes are indicated in italics in class outlines.