iii Introduction Cybersecurity is the fi eld of computer science related to protecting digital assets and computer sys- tems against unauthorized or criminal access and use. The BLS reports there are roughly 83 thousand jobs in this area with a median salary of nearly $90,000. It projects a growth of 37 percent through 2024. Demand for individuals with cybersecurity skills is expected to be very high. The Council on Cybersecurity has reported an unprecedented demand for highly skilled cybersecurity practitioners. These individuals are needed to building security into new and existing networks. They also need to be capable of assessing security on a real-time basis. These individuals are the front-line defenders against cybersecurity threats across industries and governmental agencies. Principles of Cybersecurity will prepare you with skills needed in the fi eld of cybersecurity. By studying this text, you will learn about security threats and vulnerabilities. You will learn how to identify these issues and how to combat them. This text also helps prepare you for certifi cation in CompTIA Security+ and Microsoft MTA Security Fundamentals. Cybersecurity is an advanced topic. To be successful, you should have com- pleted courses in basic computer hardware as well as networking. Many students will have obtained CompTIA A+ and CompTIA Networking+ certifi cation prior to taking a cybersecurity class. About the Author Linda K. Lavender is a cybersecurity and network administration teacher for Virginia Beach City Public Schools, Advanced Technology Center. She is also an adjunct instructor in information technology for Tidewater Community College in Virginia Beach. She holds a Master of Science in cybersecurity and a Bachelor of Science in computer information systems from Saint Leo University, Florida. She has been named teacher of the year by several organizations, including ACTE. She is certifi ed in CompTIA Security+, Network+, A+, CySA+, and CTT+ Microsoft MCTS, MCTIP, MCP, MOS, and MTA and CIW Foundations.