find, exploit or test weaknesses in systems and networks, with motivations that may include crime, espionage, protest, recreation or defensive security research. In programmer and enthusiast communities, the term has also been used positively for people who explore technical systems creatively and understand them deeply.

The word has also influenced related terms such as hackathon, civic hacking, hacktivism and life hacking. In these uses, "hacking" often refers more broadly to rapid, inventive or unconventional problem-solving ("Life hack")