Introduction to networking

In Chapter 3, Reconnaissance and Information Gathering, we learned about the basics of networking from a very high perspective. We learned about the different components and devices present in a network and what the role of each component is. In this section, we will learn a bit more about the actual packets and data that are delivered over a network.

Data representation in digital systems

Let's first understand how your computer system manages to transmit data over a network. Every part of data in a computer system is defined by binary logic levels. These levels are defined as low or high. Every image, file, video, voice recording, or anything else that is stored in a modern-day computing system is represented by these logic levels. In physical hardware, these levels are mapped to either voltage levels or switch statuses. For example, a voltage of 5 V in a digital system might represent high logic and a voltage of 0 V will represent low logic...