Interfaces vs. abstract classes
15691
Interface vs Base class
7323
What is the point of interfaces in PHP?
100909
Difference between adding a unit to the interface or the implementation section
107783
Design Patterns: Factory vs Factory method vs Abstract Factory
34805
Is it possible to make abstract classes in Python?
50304
Static vs non-static class members
21739
When to use abstract classes?
139818
Why implement interface explicitly?
39615
Polymorphism vs Overriding vs Overloading
38390
Is there more to an interface than having the correct methods
149611
Java: Why are wrapper classes needed?
42596
Why would a static nested interface be used in Java?
110878
What is the main advantage of making a class abstract
27022
The difference between Classes, Objects, and Instances
127808
Abstract class with all concrete methods
53942
Why Doesn't C# Allow Static Methods to Implement an Interface?
50570
When to use an interface instead of an abstract class and vice versa?