Database access control is the set of rules and mechanisms that determine which users, applications, or services can connect to a database and what they may do there. Permissions can limit access to particular databases, tables, or records, and restrict actions such as reading, inserting, or changing data.
These controls matter because stolen or exposed credentials can become a route to sensitive information. In real attacks, an attacker may use a valid key or account to query data; the risk depends partly on the permissions attached to it. Defenders reduce potential harm by applying least privilege, separating duties, monitoring database activity, and promptly revoking or rotating exposed credentials. Access controls help contain misuse, but they do not by themselves prove whether data was accessed or prevent every form of compromise.