In this lesson on number systems, we focus on the binary system, which utilizes only two digits: 1 and 0. Computers rely on this binary system because it simplifies processing, as they function like light switches that can either be on (1) or off (0). The data in computers is comprised of bits, which are combined into larger units such as bytes and megabytes to represent various types of information like videos and text. Understanding binary is essential as it forms the foundation of how all digital information is structured and processed.