In most cases, you can find that web page is well fit in your laptop or computers. However, in usual phones, the web page design in normal size does not fit and you cannot see the whole page at once. For iPhone, viewport concept is very essential because it determines both simple and complex web application. The display resolution of iPhone is 320×480. Therefore, the image of web page should be designed in such a way that the user can view the web page without any problem, and one can get a clear idea from such a situation.