white hat hacking

I really dont know anything about white hat hacking that is the reason for which i chose this topic.

what is the differnce between white hat hacking and other hackings?

How to do it?

http://www.secpoint.com/What-is-a-White-Hat.html

http://searchsecurity.techtarget.com/definition/white-hat

http://www.pcworld.com/article/194467/12_white_hat_hackers_you_should_know.html

• white hat hacking is also called, sneakers, ethical hacking, white knights
• The white hackers are specialized technicians that sure the safety of a companies information.
• white hacker identify the security weaknesses of a system but don't take advantage of it, they expose so that the system security can be more safe.
• the term white hat comes from a movie in which the bad guys wore black hats and the good guys wore a white hat.
• there are some white hackers that are very famous like: Robert Hansen, and Greg  Hoglund

This topic relates to my life in the sense that i want to learn how to hack and i'm usually a white hat but in the case of hacking i would like to be a black hat.

Is white hacking a profitable job?