I want to design a website without table.... "table-less website" so plz help me.... i will be very thankful to u
I would start with a template. There's a ton of free ones on the web. Search "css layouts free". http://www.freecsstemplates.org/css-templates/
Divs are an area that takes on the roles of the css id or class assigned to it. Think of it as a rectangle that is the height and width of the content inside of it. You can than apply a background color to it, borders, font color and many other things. If you combine these divs across a site and have parent and sub divs, you can create an entire site.
I agree with this... You will need to understand css inside and out if you are going to develop any website. You could probably add HTML to that list as well. Divs are pretty much blocks that hold your content in a webpage. You create the divs though HTML and add their styling via css.
Okay so you're going to need to learn some CSS. My advise is to go to http://www.w3schools.com/css/. If you want the specifics on the DIV tag visit http://www.w3schools.com/tags/tag_div.asp. Hope that helps.