Explain the principle of static resource caching and why it is needed in web development.

Caching static resources (such as CSS, JavaScript, images) in web development allows the browser to store these files locally after the first request. This reduces the number of server requests during subsequent page loads, speeds up response times, and decreases server load.

Working principle:

• On the first request, the browser receives the resource and caches it.
• The server sends headers indicating how long the resource can be stored (e.g., Cache-Control).
• On subsequent requests, the browser checks if the cache has expired and either uses the local copy or requests an updated resource.

This improves user experience through faster page loading and reduces traffic.