Hello Zahid,

I believe that the data is stored as views (QWeb) based on this video here:

https://www.youtube.com/watch?v=Xh3iCzLAH30

To view these you can go to Settings->Technical->Views and then type in the view name eg: Contact Us. You need to be in debug mode to access the technical settings. From here an example would be to search "Footer" and you will see the QWeb code for the footer of all pages. 

You can also look at the QWeb code by clicking on Customize->HTML/CSS/JS Editor while in on a website page. From here you can see the code for the view you are currently on. Using the drop-down you can select other views which are related. 

I hope this helps.

Thanks,