What is the main difference between Gridlayout and FlowLayout?
The Grid Layout provides absolute positioning for the controls placed on the page. The Developers that have their roots in the rich-client development environments such as Visual Basic will find it easier to develop their pages using absolute positioning,as they can place items exactly where they want them. On the second hand, the FlowLayout positions items down the Page such as traditional HTML. The Experienced Web developers favor this approach as it results in pages that are compatible with a wider range of browsers.
If you look into the HTML code created by the absolute positioning you can notice a lot of DIV tags. While in the Flow layout you can see more of using HTML table to position the elements which is compatible with the wide range of browsers.