BCA - Java Programming

An abstract class is one that contains at least one abstract method (i.e., an abstract method has simply a definition and no implementation, which is handled by another class).
For the Abstract class, we are unable to generate an object.

If and only if a class contains fully defined methods, it is considered to be a concrete class. Defined methods are also known as "Implemented methods" or "Concrete methods."
For concrete classes, we can create an object.