In short
KVKK is Türkiye's Law No. 6698, which sets the rules for processing personal data and the obligations of data controllers.
KVKK governs explicit consent, the duty to inform, data security measures, retention and destruction periods and data subject rights. Its scope and principles are broadly similar to the EU's GDPR.
In enterprise software, role-based access, logging and keeping data on-premise make KVKK compliance easier.