Hacking : The Internet revolution has proved to be both a blessing and a curse. Hacking if misused can create a havoc in the form of slow processing, service disruption and system failures. Hacking is a significant threat to networks exposed to the Internet.

In order to prevent systems from being hacked, the methods used by hackers must be well understood. Hacker is one who programs enthusiastically and enjoys dedicating a great deal of time with computers. Hackers are harmless technical person who likes to play with code or hardware. Normally, security flaws are used to break into computers. Hackers willingly share their knowledge on the web using simple instructions and help novices to understand hacking.

Crackers are real criminals using their knowledge or others knowledge to commit financial crimes, destroys potential servers, stole or corrupt valuable data. Crackers use few educated password guesses or a brute force attack to crack in.