Hackers are programmers who break into computer systems. Initially, hackers were simply known as programmers with interest in software creation and sharing. In fact, hackers usually place much emphasis on the importance of sharing information and have an aversion to authority and strict rules of secrecy.

This kind of culture developed and flourished in the university setting. Hackers have become more organized and systematic since then.

Many hackers do not engage in such activities with the malicious intent to steal data or destroy systems. There are hackers who simply enjoy playing around with programming and treat the activity as a mere challenge. These are sometimes called white hats. Many white hats cause security breaks for learning purposes, as well as for testing their own systems.

Hackers who try to break into systems for the purpose of stealing information or of causing systems to collapse are oftentimes referred to as crackers. They may be also known as black hats. They may use their know-how to spread malware, such as trojans, worms, and viruses. Black hats may also try to commit credit card fraud, information or identity theft,

On the other hand, hackers who belong to the underground community of programmers and engage in activities to support this movement or other ideological, religious, or social causes are known as hacktivists. One of the most common cyberattacks launched by hacktivists is website defacement.

Since hackers differ in their beliefs and motivations for the activities they engage in, many align themselves with specific groups in order to establish their identities and differentiate themselves from those who do not share the same interests or motivations.