The document is a lecture on an introduction to data structures. It discusses the goals of understanding basic data structure types and their applications. It provides examples of how data structures are used in task management, word reversal, bus queueing, job printing, and network packet storage. Common data structure applications include slide navigation, web page navigation, name directories, and image viewers. Data structures also help organize files, maps, and social networks. There are two main types of data structures - one dimensional and multi-dimensional. A data structure is a specialized format for organizing data in computer memory so a program can effectively use it to represent the logical relationships between data elements.