Understanding of interfaces in c #

In my understanding, an interface is used to identify the type of a class.

For example, if there is an Interface: an animal, whether it is the class: cat, dog, ox, etc,

As long as it inherits the animal interface, it is necessary to implement the method defined by the animal interface.

At the same time, as long as we see that a class inherits the animal interface, we can boldly call the method defined by the interface.

In addition, a class in c # can inherit multiple interfaces, that is, a class can have multiple types.

For example, a person may be a parent's son, a wife's husband, or a company employee.

Importantly, if there are many small classes in the project, and some classes have something in common (methods, attributes, etc ),

We can define an interface for these classes to inherit.

In this way, when classes A, B, and C all inherit the same interface, we only need to be familiar with the use of one of the classes,

It is very convenient to use other classes.

However, when the project is implemented in a single way, that is to say, defining an interface can only be implemented by a class.

When other classes are not used, we do not need to use interfaces.

This will only increase the complexity of the Code.

Therefore, when designing the project architecture, we should consider the situation and then use the interface.