how html will help us in designing the wedsite?

it seems that you dont really understand what is HTML, if you using frontpage,notepad, dreamweaver,homesite and other HTML editor software you are make an HTML page by creating several HTML tags. HTML is the core of web page mean you cant do nothing without HTML else your web page will only contain flat text. frontpage and dreamweaver are the sample of WYSIWYG HTML editot, NOtepad,Homesite are the samples of Hard Code HTML editor and those all are only tools that helping you to make you HTML Page.

Not for the designing part, but the HTML/coding part, yes. I've never used Front Page though. I use Macromedia Dreamweaver, but you deisgn the site in another program like Photoshop, FIreworks, or Flash, then code it all together so it's functional using Front Page.

That's irrelevant. HTML just does the main part of the web showing, it's the code that shows the layout, images, and others. You should ask How PHP, or ASP.Net will help us, they're a lot more useful.