Application Cache in HTML5
Yet HTML5 has many new special elements and attributes, but one of the best features of HTML5 is "Application Cache", that enables us to make an offline session of a web application. It allows to fetch
few or all of websites contents such as HTML files, images, JavaScript, CSS
...etc. This feature speeds up the site performance. This is achieved with the
help of a file, defined as follows :
- <! doctype html><html manifest="example.appcache">
- ....
- ....
- .....
- </html>

Jack OwensPosted Jul 19, 2013, 9:13 PM
This URL https://www.youtube.com/watch?v=kXZA9eS6nCw explains it in detail