what is hacking ?

Hacking is the practice of modifying the features of a system, in order to accomplish a goal outside of the creator's original purpose. The person who is consistently engaging in hacking activities, and has accepted hacking as a lifestyle and philosophy of their choice, is called a hacker.

Computer hacking is the most popular form of hacking nowadays, especially in the field of computer security, but hacking exists in many other forms, such as phone hacking, brain hacking, etc. and it's not limited to either of them.

Due to the mass attention given to blackhat hackers from the media, the whole hacking term is often mistaken for any security related cyber crime. This damages the reputation of all hackers, and is very cruel and unfair to the law abiding ones of them, from who the term itself originated.

source of information http://whatishacking.org/