The reason you would want to do this is if you want to redirect your website visitors to another website but not display the destination web address. Here is how you do it.
Login to your cPanel and go to File Manager/Web Root
Click on New File and name it index.html
Then right click the index.html file and select edit
Now go to the webstart Forward website.
Scroll down to How do I create a masked forward? (frames)
Enter the Title
Then enter the destination url and click submit
This will then generate the code that you need to paste into your index.html file
Save your index.html page
That is it, whenever you go to your website it will redirect while showing your website.