CORS (Cross-Origin Resource Sharing) is a security feature implemented in browsers that allows controlling which resources can be requested from a different domain than the one from which the web page originates. CORS is important because:
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Security: It prevents unauthorized requests to resources on different domains, protecting against attacks like Cross-Site Request Forgery (CSRF).
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Access Control: It allows servers to specify which domains can access their resources using headers like
Access-Control-Allow-Origin
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Enhanced Functionality: With CORS, it's possible to create applications that can safely request resources from multiple domains, which is essential for many modern web applications.
Example CORS headers:
Access-Control-Allow-Origin
: Specifies which domains can access the resources.Access-Control-Allow-Methods
: Specifies which HTTP methods are allowed during requests.Access-Control-Allow-Headers
: Specifies which HTTP headers can be used during requests.
Understanding CORS is crucial for building secure and efficient web applications that need to communicate with resources on different domains.