Cyber security is the practice of protecting critical systems and sensitive information from digital hackers. Also known as information technology (IT) security, cyber security measures are designed to combat threats against networked systems and applications, whether those threats originate from inside or outside of an organization. Cyber security is the practice of protecting critical systems and sensitive information from digital attacks. Also known as information technology (IT) security, cyber security measures are designed to combat threats against networked systems and applications, whether those threats originate from inside or outside of an organization.