This document discusses hacking and provides information on:
1. The introduction of hacking and what hacking is - the practice of exploiting computers to access unauthorized information.
2. The different types of hacking including ethical hacking and unethical hacking.
3. Hacking techniques such as password cracking, packet sniffing, and social engineering.
4. What to do if a system is hacked, including shutting down the system and restoring from backup.