Hacker

Someone who breaks into computer systems in order to steal, change or destroy information.

Someone who is brilliantly persistent in solving technical problems, whether these involve golfing, fighting orcs, or programming. Hacker is a neutral term, morally speaking. Good hackers are not to be confused with evil crackers or clueless script kiddies. If you confuse them, we will presume that you are either evil or clueless.

A person with special expertise in computer systems and software. A hacker who attempts to gain unauthorized access to computer systems is a “cracker.”

A person who breaks into, or attempts to break into, or use, a computer network or system without authorization , often at random, for personal amusement or gratification, and not necessarily with malicious intent. 2. [An] unauthorized user who attempts to or gains access to an information system (IS). [INFOSEC-99] 3. A technically sophisticated computer expert who intentionally gains unauthorized access to targeted protected resources. [After ANSDIT] 4. Loosely, a computer enthusiast. [ANSDIT] 5. A person who uses a computer resource in a manner for which it is not intended or which is in conflict with the terms of an acceptable-use policy, but (unlike the work of a cracker) is not necessarily malicious in intent.