I have been programming in Java for about four years and now, I have come to know from my senior and my school computer teacher that "Multiple inheritance is also known as an interface." But I don't think it's true because with the knowledge that I have learnt so far, an interface is a special type of class which have static variables and abstract methods which can be implemented into classes. I want to clarify this doubt of mine. Please help!
Multiple inheritance is also known as an interface.
I would say that's not very accurate, and is a little bit misleading.
What your senior/teacher probably mean is that in Java multiple inheritance is implemented through interfaces. Since Java doesn't allow a class to extend only one other class directly, the only way to have multiple inheritance in Java is to implement multiple interfaces. This is not the case in some other object-oriented languages (like C++).
You can find some good background reading on why Java doesn't allow direct multiple inheritance of classes in the article Java and Multiple Inheritance.