DEF CON is a hacker convention held annually in Las Vegas, Nevada. The first DEF CON took place in June 1993 and today many attendees at DEF CON include computer security professionals, journalists, lawyers, federal government employees, security researchers, students, and hackers with a general interest in software, computer architecture, hardware modification, conference badges, and anything else that can be "hacked". The event consists of several tracks of speakers about computer- and hacking-related subjects, as well as cyber-security challenges and competitions. Contests held during the event are extremely varied and can range from creating the longest Wi-Fi connection to finding the most effective way to cool a beer in the Nevada heat.

A computer security conference is a convention for individuals involved in computer security. They generally serve as meeting places for system and network administrators, hackers, and computer security experts.