How is inheritance implemented for abstract classes in object-oriented programming?

In C#, an abstract class is a class that cannot be instantiated directly and can contain abstract methods (without implementation). Inheritance from an abstract class is implemented using the : keyword, and the derived class must implement all abstract methods.

Example:

abstract class Animal
{
    public abstract void MakeSound();
}

class Dog : Animal
{
    public override void MakeSound()
    {
        Console.WriteLine("Bark");
    }
}

Here, the Dog class inherits from Animal and implements the abstract method MakeSound. This allows creating class hierarchies with a common base and different specific implementations.