Web Development
web
security
api
What is CORS?
Definition
CORS (Cross-Origin Resource Sharing) is a browser security mechanism that controls which domains can make requests to your API. It uses HTTP headers (Access-Control-Allow-Origin) to allow or block cross-origin requests.
Why It Matters
CORS errors are among the most common issues in web development. When your frontend at app.com tries to call an API at api.com, the browser blocks it unless the API sends proper CORS headers. Understanding CORS saves hours of debugging.