The CACHE section lists all resources that should be downloaded and stored locally. The browser will begin downloading these in the background as soon as the page has loaded. If any are already in the browser’s cache, they will not be downloaded again separately.

The NETWORK section lists all URLs that may be loaded over the Internet. If your application includes any API calls, make sure to enumerate them here. Note that this is a list of URL prefixes, so if all of your network calls begin with http://example.com/api/, that’s all you need to include.

If you want to allow arbitrary URLs to be accessed (scripts, stylesheets, API calls, anything), include * , http://* and https://* in this section. (Chrome and Safari respect the * ; Firefox needs the http://* and https://* .)

The FALLBACK section lists replacements for network URLs to be used when the browser is offline or the remote server is unavailable.

The SETTINGS specifies settings for appcache behaviour. Currently, the only available setting is cache mode.