Google Cache is normally referred as the copies of the web pages cached by Google. Google crawls the web and takes snapshots of each page as a backup just in case the current page is not available. These pages then become part of Google's cache. These Google cached pages can be extremely useful if a site is temporary down, you can always access these page by visiting Google’s cached version.
Google 缓存通常被称为 Google 缓存的网页副本。Google 会抓取网络并拍摄每个页面的快照作为备份，以防当前页面不可用。然后，这些页面成为 Google 缓存的一部分。如果站点暂时关闭，这些 Google 缓存的页面可能非常有用，您始终可以通过访问 Google 的缓存版本来访问这些页面。
Google web is usually updated in a few days. The actual time of the updates depends on the frequency the website updates itself.
Google 网络通常会在几天内更新。更新的实际时间取决于网站自我更新的频率。
Coral Cache, also known as Coral Content Distribution Network or Coral, is a free peer-to-peer type web cache based on thepeer-to-peer content distribution network designed and operated by Michael Freedman. Coral uses the bandwidth of a world-wide network of web proxies and nameservers to mirror web content, often to avoid the Slashdot Effect or to reduce the load on websites servers in general.
Coral Cache，也称为 Coral 内容分发网络或 Coral，是一种免费的点对点类型 Web 缓存，基于由 Michael Freedman 设计和运营的点对点内容分发网络。Coral 使用全球网络代理和名称服务器的带宽来镜像 Web 内容，通常是为了避免 Slashdot 效应或减少网站服务器的负载。
Coral Cache is ususally not updated as frequently as Google web cache.
Coral Cache 的更新频率通常不如 Google 网络缓存。
The Archive.org, also known as Wayback Machine, is a digital archive of the World Wide Web and other information on the Internet created by the Internet Archive, a non-profit organization, based in San Francisco, California. It was set up by Brewster Kahle and Bruce Gilliat, and is maintained with content from Alexa Internet. The service enables users to see archived versions of web pages across time, which the Archive calls a three dimensional index.