What is Cross Origin Resource Sharing (CORS)?

Cross-Origin Resource Sharing (CORS) is a web security mechanism that allows web applications to access resources from different domains while maintaining security. It overcomes the restrictive Same-Origin Policy by introducing HTTP headers that specify which origins can access server resources, facilitating secure data exchange across microservices and third-party APIs. CORS is vital for modern web development as it enhances functionality, user experience, and compliance with web standards. It involves server and client-side configurations, applicable across various frameworks like Apache, Nginx, React, and Angular. While it enables resource sharing, developers must adhere to security best practices, such as specifying allowed origins and using the Access-Control-Allow-Credentials header cautiously, to prevent vulnerabilities. CORS should be part of a broader security strategy, including authentication and data validation, to ensure robust web application security.