is a technique which is taken from real world in order to simplify development and maintenance of the software. There are so many concepts like object class inheritance encapsulation polymorphism etc. collectively all the concepts are called OOPS. If a language is having all the characteristics of OOPS is called object Oriented programming language . Java follow object oriented concepts ,so java is an object programming language. In OOPS we have to create an object (eg simula, java, c++, .net).
And the concepts like inheritance and polymorphism of object oriented is not followed by any language then its called object based programming language.in object based we have readymade objects like in ( php,javascript).
Programming language if a language have everything in the form of objects no support of primitive datatype and no support of static keywords that language is called PURE. (smalltalk).
But java is not a pure because java is default primitive type and support of static keyword.