- A web worker is a JavaScript which runs in the background. It exists in external files. 

 - It is independent of other scripts and does not affect the performance of the page. 

 - Web workers are usually used for CPU intensive tasks.

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

The Application Cache concept introduced by HTML5 means that a web application is cached, and accessible without an internet connection.

There are three advantages of Application Cache:

1.Offline browsing - users can use the application when they're offline

2.Speed - cached resources load faster

3.Reduced server load - the browser will only download updated/changed resources from the server

- localStorage object stores the data without an expiry date while sessionStorage object stores the data only for one session. 

- With localStorage object, data will not be deleted when the browser window is closed while the data is deleted when the browser window closes with sessionStorage objects.

With HTML5, it is possible for the web pages to store the data locally in the user's browser. This web storage is much faster and secured than the cookies. Also, a larger amount of data can be stored without causing any adverse effect to the performance of the website. 

The data here is not included with every server request. It is used ONLY when it is asked for. It is only that particular web page that can access the data stored by itself.

Some important differences between Canvas and SVG:

- Canvas is resolution dependent while SVG is not. 

- Canvas does not provide any support for event handlers while SVG does. 

- Canvas is suitable for graphic-intensive games while SVG is not suitable for gaming.

- Canvas is suitable for small rendering areas while SVG is suitable for large rendering areas like Google maps.

Canvas is a rectangular area on a HTML page, specified with the tag <canvas>. 

- SVG is the abbreviation for Scalable Vector Graphics and is recommended by W3C. 

- It is used to define vector-based graphics for the Web

- The graphics are defined in XML format

-An important quality of SVG graphics is that their quality is maintained even when they are zoomed or resized. 

- All the element and attributes of SVG files can be animated