Fetch API

Summary

The modern, Promise-based browser API for making HTTP requests — the standard replacement for the older `XMLHttpRequest`. Fetch separates request creation from response parsing and provides a Promise-based interface for headers, status, bodies, streaming, and different HTTP methods.

• 1Fetch data from a public API and handle both success and error cases. Validate your understanding by applying it in a small practical example.
• 2Learn how to send a POST request with a JSON body and headers. Focus on understanding the underlying reason it works, not only memorizing the definition.
• 3Check `response.ok` for HTTP errors — `fetch` only rejects on network failure.