Definition
A cached page is a snapshot or a stored version of a web page taken at a specific time and saved by a web browser or a search engine. This cached version allows users to view the content of a web page even if the original page is temporarily unavailable, has been updated, or the user is offline. Caching serves as a way to reduce loading times, decrease server load, and improve the overall user experience by providing quick access to previously visited pages.
Types
- Browser Cache: Most web browsers store copies of web pages visited by a user on their local device. This cache includes HTML files, CSS stylesheets, JavaScript files, and multimedia content, enabling the browser to load these pages more quickly on subsequent visits.
- Search Engine Cache: Search engines like Google, Bing, and Yahoo cache web pages when they crawl and index the internet. Users can access these cached pages through search results, often via a “Cached” link next to the page’s search listing. This is particularly useful for accessing a page’s content when the website itself is down or loading slowly.
- Content Delivery Network (CDN) Cache: CDNs are used to distribute website content globally to servers closer to users, reducing latency. When a user requests a webpage, the CDN serves the content from the nearest server with a cached version, if available, to speed up delivery.
- Proxy Cache: Some organizations and ISPs use proxy servers to cache web content. This type of cache reduces bandwidth usage and improves access speed for users within the network by serving cached content from the proxy server instead of the original server.
Examcaples
- Browser Cache Example: After visiting a news website, the site’s content is stored in your browser’s cache. When you revisit the site, your browser loads it from the cache, significantly reducing the page load time.
- Search Engine Cache Example: If a blog post has been updated or removed, you can still access the previous version of the post through the cached link provided by a search engine in its search results.
- CDN Cache Example: When accessing a video streaming service, the content might be served from a CDN’s cache located geographically closer to you, ensuring smooth playback without buffering.
- Proxy Cache Example: In a corporate setting, frequently accessed external websites might be cached by a proxy server, so employees can access these sites more quickly and reduce external bandwidth usage.