If the data is arranged or organized by applying some rules, it adds to the efficiency of operations. Here one need to understand context of the word efficient. According to author (Shaffer, March 28, 2013), efficiency of any algorithm is defined as to give the solution within available constraints, where constraints are available memory and processor time. Basic objective of any ADT and consequently Data structure is to arrange stored data in a way which gives efficient access to data. With intension of adding efficiency to structure some extra information about data is being stored along with actual data known as 'Overhead'.