A permission set is the collection of access rights assigned to a user, group, or application. It defines what actions are allowed, such as viewing records, exporting data, editing settings, or administering a system. In cyber security, permission sets are a core part of least privilege: each account should have only the access it truly needs.
Permission sets matter because overly broad or misconfigured rights can turn a small compromise into a major breach. If an attacker steals one account, an excessive permission set may let them reach sensitive files, change security settings, or pull data from internal tools. Defenders reduce this risk by reviewing roles regularly, removing unused privileges, separating duties, and logging permission changes so unusual access stands out quickly.