Div tag is just container for any another html element. Frameset is structure for making frame. All today's website are built based on div tags creating layout of website. Frameset were used for website's layout in the past but SEO does not recommend them any more.
Read here: http://www.dreamincode.net/forums/topic/16442-div-vs-frames/ Also you must atleast try searching the answer (through google) before created a new post.