This document provides an introduction and overview of digital signal processing. It defines signals and how they can be classified as continuous or discrete, continuous or discrete valued. It describes how analog signals are converted to digital signals through sampling and quantization. It explains that digital signal processing involves passing signals through systems to process the signals. It outlines some key advantages of digital signal processing over analog processing, such as flexibility, accuracy, and easy storage. Finally, it provides some examples of applications of digital signal processing like voice recognition, telecommunications, consumer electronics, imaging, and more.