In this lesson, the focus is on operating systems, specifically for fifth-year students, covering the definition and types of interfaces. The teacher explains that an operating system is a type of system software that controls how a computer handles user requests, distinguishing it from hardware. Students will learn about command line interfaces versus graphical user interfaces and the importance of knowing what an operating system does, as well as recognizing different operating systems like Microsoft Windows and macOS. The session aims to deepen students’ understanding of system software and how it functions within computers and devices.