How is a "security breach" defined?

A security breach is defined as an incident where unauthorized parties gain access to sensitive data or systems. This could involve hackers infiltrating a network to steal personal information, financial data, or confidential business details. A security breach poses significant risks, including data theft, financial loss, and reputational damage to an organization.

The other scenarios listed do not qualify as security breaches. For instance, forgetting a password does not involve unauthorized access; it simply relates to user authentication issues. Server maintenance is a routine operational procedure aimed at ensuring system reliability, not an incident of unauthorized access. When an employee leaves an organization, it does not inherently involve a breach unless sensitive information is compromised, which is a separate issue entirely. Thus, the definition focused on unauthorized access is the most accurate understanding of a security breach.