Template

Let's understand

💡 tea and coffee are made in very SIMILAR way: they follow the same preparation algorithm: boil water pourIncup brew coffee grind add sugar and milk

We still have different methods But they are actually similar : adding sugar and milkk or adding Lemon are both "adding"

Let's meet the Template Method

we can notice that the boilWater() and pourInCup() are not abstract because they have the same implementation in all subclasses

If we have a method that could be exsiting in some classes and other not, all you have to do is declaring it as a concrete method with an empty body, this means that subclasses can override it but it is not an obligation : these methods called hook

Diagram