Cybersecurity is the protection of confidentiality, integrity and availability of information within an organisation. Confidentiality is a set of rules that limit access to information. Integrity is the assurance that the information is trustworthy and accurate. Availability is a guarantee of reliable access to the information by authorised people.
One of the most problematic elements of cybersecurity is the quickly and constantly evolving nature of security risks. The traditional approach has been to focus most resources on the most crucial system components and protect against the biggest known threats, which necessitated leaving some less important system components undefended and some less dangerous risks not protected against.