PostgreSQL's Row Level Security (RLS) is a database feature that shifts permission verification from the application layer to the database itself, providing stronger safety by preventing unauthorized data access and ensuring consistent enforcement of security policies across all queries. Traditionally, permissions are managed at the application level, but this can lead to scattered checks, inconsistencies, and potential data leaks. RLS addresses these issues by enforcing policies directly within the database schema, transforming PostgreSQL into a trusted enforcer of access control. This approach, while enhancing security, introduces new challenges in schema design, debugging, and operational workflows that require developers to adapt their practices and deepen their understanding of database management. RLS is best suited for applications where safety, consistency, and regulatory compliance are paramount, but it necessitates careful consideration of performance implications and a cultural shift in how teams approach database access control.