The document provides an introduction to data structures. It defines data structures as representations of logical relationships between data elements that consider both the elements and their relationships. Data structures can be primitive, directly operated on by machine instructions, or non-primitive, built from primitive structures. Non-primitive structures include linear structures like stacks and queues and non-linear structures like trees and graphs. Arrays are introduced as a basic data structure that stores homogeneous elements in contiguous memory locations. Common array operations like traversal, searching, sorting and merging are described. Two-dimensional arrays and their row-major and column-major representations are also covered.