This document discusses cyber security and defines key related terms. It explains that cyber security is needed to protect online data and systems from threats like data theft or viruses. Some major security problems are identified as viruses, hackers, malware, Trojan horses, and password cracking. The document provides information on each of these threats and recommends solutions like installing security suites, using strong passwords, and being cautious of emails. It concludes by emphasizing that cyber security is everyone's responsibility.