What is a Manifest file?

A Manifest file is a simple text file that tells the browser what to cache and what not to cache.
There are three sections of a Manifest file:
i.) CACHE MANIFEST - Files listed here are cached after they are downloaded for the first time.
ii.) NETWORK - Files listed here require a connection to the server, and are never cached
iii.) FALLBACK - Files listed here specify fallback pages if a page is inaccessible