Hacker

Hacker is a term often applied to computer software or computer hardware programmers, designers and administrators, especially those who are perceived as experts or highly accomplished in this field. A hacker is also a term used for someone who modifies electronics such as ham radio transceivers, printers or even home sprinkler systems for better functionality or performance. The term usually bears strong connotations that may be favorable or pejorative depending on cultural context (see the hacker definition controversy).
In computer programming, a hacker is a software designer and programmer who builds programs and systems that garner the respect of one's peers. A hacker may also be a programmer who reaches a goal by employing a series of modifications to exploit or extend existing code or resources. For some, "hacker" has a negative connotation and refers to a person who gains illegal access to computers (hacks) or uses kludges to accomplish programming tasks that are ugly, inelegant, and inefficient. This derogatory form of the noun "hack" is even used among users of the positive sense of "hacker" (some argue that it should not be, due to this negative meaning; others argue that some kludges can, for all their ugliness and imperfection, still have "hack value").
In computer security, a hacker is a person who specializes in work with the security mechanisms for computer and network systems. While including those who endeavor to strengthen such mechanisms, it is more often used by the mass media and popular culture to refer to those who seek access despite these security measures.
In other technical fields, hacker is extended to mean a person who makes things work beyond perceived limits through their own technical skill, such as a hardware hacker, or reality hacker.