Hacker vs Cracker

Cracker
The definition of a cracker is one who attempts to break into a system using techniques that he does not fully understand. Most of the crackers are young teenagers who are very malicious and seek to get their kicks from destroying or alternating data on a system.

Hacker
The hacker on the other hand is an individual who yearns for knowledge. Very knowledgeable individuals, that often know several programming languages, work extensively with the inwards and outwards of UNIX, have a firm understanding of all the TCP/IP implementations and protocols and keep abreast on all the security related issues involving computers.
Breaking into a system for a hacker is a thrill, it is a challenge that they take on. The hacker takes much delight in exploring the system from the outside/inside searching vigorously for misconfigurations, bugs, and holes in the operating system that would allow them to break into a machine. Once in the system the challenge has been completed and they have succeeded in breaking in. It is against hacker ethics to alter any data aside from the logs that are needed to clean their tracks. They have no need or desire to destroy data as the malicious crackers. They are there to explore the system and learn more. The hacker has a constant yearning and thirst for knowledge that increases in intensity as their journey progresses.