Cross-origin resource sharing (CORS) is a browser mechanism which enables controlled access to resources located outside of a given domain. It extends and adds flexibility to the same-origin policy (SOP). However, it also provides potential for cross-domain attacks, if a website's CORS policy is poorly configured and implemented. CORS is not a protection against cross-origin attacks such as cross-site request forgery (CSRF).
Firebase Authentication provides backend services, easy-to-use SDKs, and ready-made UI libraries to authenticate users to your app. It supports authentication using passwords, phone numbers, popular federated identity providers like Google, Facebook and Twitter, and more.
Usually, authentication by a server entails the use of a user name and password. Other ways to authenticate can be through cards, retina scans, voice recognition, and fingerprints.
The private route component is similar to the public route, the only change is that redirect URL and authenticate condition. If the user is not authenticated he will be redirected to the login page and the user can only access the authenticated routes If he is authenticated (Logged in).
Node. js is a JavaScript runtime environment that achieves low latency and high throughput by taking a “non-blocking” approach to serving requests. In other words, Node. js wastes no time or resources on waiting for I/O requests to return.