A person who writes programs in assembly language or in system-level languages, such as C. The term often refers to any programmer, but its true meaning is someone with a strong technical background who is "hacking away" at the bits and bytes.

Hackers Have a Bad Name
During the 1990s, the term "hacker" became synonymous with "cracker," which is a person who performs some form of computer sabotage. The association is understandable. In order to be an effective cracker, you had to be a good hacker, thus the terms got intertwined, and hacker won out in the popular press.

However, sometimes, hackers are not even worthy of the original meaning of the term. Today, a lot of malicious acts are performed by people with limited knowledge who gain unauthorized entrance into computers to steal data or perform mischief (see script kiddie). See cracker, hack, white hat hacker and samurai.