Imagine that you are the boss of a factory, any factory producing any product you could imagine. You have a perfect creational algorithm that is being used. However, one day you decide to expand your business and open one more factory in another city. That means that you have to encapsulate your creational algorithm for old and new factories. This is what the Abstract Factory is about.

Template Method is a behavioral pattern that describes the common algorithm while subclasses implement steps of this algorithm. This pattern lets the subclasses implement the steps of the algorithm without changing that algorithm's skeleton.

The Factory Method pattern is a good place to start, especially if you wish to understand the concept of other factory patterns. It is probably the simplest one and you can implement it for sure.

You probably have heard of behavioral patterns by now. Behavioral patterns are concerned about the interaction of objects. While there are about 12 design patterns that belong to behavioral patterns, the command pattern takes a special place as it is used more often than other design patterns. The purpose of the command pattern is to decouple the logic between command and its consumers.

Sometimes we have a hierarchy of classes with one base class (or interface) and several subclasses, and we need to create a new subclass object depending on its type. Instead of writing a new operator in client code where we will use the objects, it is convenient to encapsulate the code for creating objects in a separate place and call it from the client code. These places are known as factories that produce instances of classes related to the same hierarchy. They allow us to simplify the client code and protect it from changes when new classes are added to the hierarchy.