This document discusses the importance of security for computers and networks. It identifies common security threats both internal and external, such as employees, hackers, viruses, worms, and social engineering. The document also outlines different types of attacks including physical theft or damage of equipment, data theft or corruption, and various forms of malware like adware, spyware, phishing, trojans, and rootkits. Finally, it recommends security procedures like creating strong passwords, developing security policies, and maintaining up-to-date software and antivirus protection.