1) In quality assurance, tweaking is the process of making subtle variations in the environment in which a program is tested in order to produce unanticipated behaviors. Such tweaking can involve system configuration, hardware configuration, unusual system conditions (e.g. heavy traffic, memory shortage/availability conditions, physical resource shortage/availability conditions, simulated and actual virus attacks, unusual message input, unusual message input node, loss of signon status), and other relevant but low-probability situations which may not have been anticipated by the designer or developer.
2) In general a tweak freak (also known as a tweaker ) is a person who tinkers with hardware and/or programming to a point approaching obsession. Sometimes the intent is to enhance system performance beyond the norm. But many tweak freaks engage in the activity largely because it is interesting, fun, and can be a learning experience. It can also be frustrating and at its worst, dangerous.
The term "tweak" may have originated in the early days of electronics, when tweezers were used to adjust the position of a wire on a crystal of galena in order to detect amplitude-modulated ( AM ) radio broadcast signals. Nowadays, hardware and programs of all kinds can (and often should) be aligned or debugged for optimum performance; technicians and programmers call the process tweaking.
The tweaking of computers, especially software and operating systems, is not for the faint-of-heart. Excessive or improper tweaking can cause computers and Web browsers to become unstable. Vulnerability to virus or Trojan horse infection may be increased. Excessive downloading and installation of tweaks and patches can increase the probability of program conflicts and crashes. Some tweaks facilitate illegal or questionable use of the Internet, and should be avoided by people who respect the law and the rights of others (and who wish to stay out of court). Let the tweaker beware.