How web applications are secured

Web application security involves protecting backend code and databases by using a server-side component such as a REST API. Authentication is key to verifying user identities through tokens or session IDs. Authorization ensures users have proper permissions to access data. Middleware functions check token validity to prevent unauthorized access. Rate limiting can protect servers from being overwhelmed by repeated requests. Input validation and sanitization are crucial to prevent storing malicious data that could harm the application or other users.