This document provides an introduction to data structures. It defines data as distinct pieces of information that can exist in various forms, such as numbers, text, bits and bytes. It defines data structure as a way to organize data so it can be used efficiently. Common data structures include arrays, lists, stacks, queues and files. The document outlines some important data types like integer, boolean, floating, character and string. It also discusses basic operations on data structures like traversing, searching, inserting, deleting, sorting and merging. Finally, it provides examples of different data structures and their applications.