Sometimes you might want your image to be positioned at a specific place, for example, you might not want the image to have margins when viewed from a browser even when it is positioned at the top left corner. In this case, you could use this code to position your image. I have, by default, entered '0px' for the left position and top position. You can increase the value to move the image round the page. This could be particularly useful when you want your layout to stick to the top and to the left, without a white margin in between the picture and the browser's grey margins.