With the concept of objects, object based languages promote the idea of reusability, an important technique in software engineering today. Object based language have been used widely in many areas. It also supports records. A record is a collection of heterogeneous variables. Different from Pascal, object based languages allow to have objects.
Objects use messages to communicate to each other.
The only thing that an object knows about another object is the other object' s interface. Private data members and methods are hidden. An object can also inherit attributes from parent objects. Smalltalk is a truly object based language. All of data types are objects.