In general, a reference is a relation between objects in which one object designates by linking to another object. Such relations as these may occur in a variety of domains, including logic, computer science, time, art and scholarship. Although the objects which the term reference applies may be of a varying character ranging from concrete examples such as reference work which includes pointers or symbols. The nature of reference as a role in language and thought has been around since the 19th Century. During this time, applying itself as an important topic of discussion. An object which is referred to as a reference (where the reference leads) is called a referent.