IT Concept: CORS (Cross-Origin Resource Sharing)
A browser security mechanism that controls which web origins can access resources from a different origin.
CORS (Cross-Origin Resource Sharing) — A browser-enforced security policy that blocks cross-origin HTTP requests by default. Servers opt in by sending headers like Access-Control-Allow-Origin. Preflight OPTIONS requests are triggered by non-simple methods or custom headers. Understanding CORS is essential for SPA + API architectures.