[dudeson]

Hacker for me is someone who knows what he is doing. Hacker is someone that from his solid knowledge at something (not necessarily "software engineering") can achieve his goal. His goal might be gaining an unauthorised access into a system or creating a piece of hardware that will make his life easier, or even having free drinks/snacks from a vending machine.

Having deep knowledge at something and being able to do what you want with it, makes you a hacker.

Note that sometimes there is a confusion with hackers and script kiddies. Script kiddies in short are those with little or no real knowledge use instructions and tools causing damage only.

Hope this helped.