Abstract Classes
An abstract class is a class in object-oriented programming (OOP) that cannot be instantiated. Instead, it serves as a template or blueprint for other classes to inherit from. An abstract class can contain both abstract and non-abstract methods (abstract methods are methods that do not have any implementation, they just have a signature).
Abstract classes are used to provide a common interface and implementation for a group of related classes. They are also used to define common behavior that must be implemented by all subclasses. A subclass that inherits from an abstract class is called a concrete class, and it must provide an implementation for all the abstract methods declared in the parent class.
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