Discretionary Access Control (DAC) is a security model that allows the owner of a resource, such as a file or folder, to determine who can access it. In this system, the owner has the discretion to grant or restrict access to other users based on their preferences. This means that users can share their resources with others or keep them private, depending on their needs. In DAC, permissions are typically assigned to users or groups, allowing for flexible management of access rights. For example, a user can set permissions for their documents so that only specific colleagues can view or edit them, while others are denied access.