This document discusses data structures and algorithms. It defines data as information that has been organized for processing or movement. A data structure is a way of organizing data so it can be used effectively, with examples like arrays and linked lists. An algorithm is a step-by-step procedure for solving a problem, and can use one or more data structures. There are two types of data structures: primitive/built-in ones that store a single data type, and non-primitive/user-defined ones that can store multiple types, like arrays and linked lists. Data structures are also classified as linear, with elements in sequence, or non-linear, with non-contiguous elements arranged hierarchically like trees and graphs.