Read/write privileges are permissions that let a user or service account view data and change it. In databases, file systems, and cloud services, these rights are powerful because they can alter records, configuration, or content, not just inspect it. A compromise of an account with write access can therefore have a much larger impact than a read-only account.
In cyber security, read/write privileges matter because attackers often target accounts that already have legitimate access. If a vulnerable application, script, or database feature is reachable by a trusted account, an attacker may be able to modify data, plant malicious changes, or disrupt availability without needing to break perimeter defenses. Defenders limit this risk with least privilege, role-based access control, tight service-account scoping, logging, and periodic review of who can write where.