How do abstract classes relate to abstract factories or strategy patterns?

• Abstract classes often define base contracts or template methods for patterns:
• Abstract Factory: Defines abstract methods to create families of objects.
• Strategy Pattern: Abstract class defines a common interface for

interchangeable algorithms.

abstract class PaymentStrategy

public abstract void Pay(decimal amount);

class CreditCardPayment : PaymentStrategy

public override void Pay(decimal amount) =>

Console.WriteLine($"Paid {amount} by credit card");