• Data can be organized in many different ways. The logical or mathematical model of a organization of data is called a Data Structure
•  A data structure is a collection of data values, the relationships among them, and the functions or operations that can be applied to the data,

NEEDS OF DATA  STRUCTURE--

• The computer are electronic data processing machine. In order to solve particular problem we need to know:

             1-- How to represent data in computers?

             2-- How to access them?

             3-- What are the steps we need to perform to get the needed output

     These task can be achieved with the knowledge of data structure and algorithm.

CLASSIFICATION OF DATA STRUCTURE---

• Data structure are classified into PRIMITIVE and NON-PRIMITIVE data structures

               1-> PRIMITIVE DATA STRUCTURE  

                      --   These are the fundamentals standards data types.

                      --  These are used to represent single values .

                      example- int, float, char, double

               2->  NON-PRIMITIVE DATA STRUCTURE

                      -- These are derived from primitive data types

                      --  Used to store group of values

                      example- arrays, stacks, queues, trees etc.

• Based on the structures and arrangement of data, non-primitive data structures are further classified into linear and non-linear.                   

            LINEAR DATA STRUCTURE--

           >  A data structure is said to be linear if its elements form a sequence or a linear list

           > In linear data structures, the data is arranged in a linear fashion although the way they are stored in memory need not be sequential

            example- Arrays, linked list etc

            NON-PRIMITIVE DATA STRUCTURE--

           > A data structure is said to be a non-linear if the data is not arranged in sequence. 

           > The insertion and deletion of data is therefore not possible in a linear fashion

           example- trees, graphs