In this lesson, you will examine the purpose of IT certifications, with specific emphasis on CompTIA Network+ and how it fits into the career of a network tech. You will explore how networks work in general, covering such essential concepts as servers and clients, Ethernet, switches, and LANs. In the last two sections of the lesson, you will examine two different models that technicians use to troubleshoot networks: the OSI seven-layer model and the TCP/IP model.