Typing is the enforcement of the class of an object, such that objects of different types may not be interchanged or at the most, they may be interchanged only in very restricted ways.
It is technique for defining software components that have more than one interpretation depending on the data type of parameters. Thus it allows the declaration of data items without specifying their exact data type.
Although the concept of type & class seems to be similar but typing emphasis upon the meaning of abstraction. A type is a precise characterization of structural or behavioral properties.