The structure of a Web page is imposed by the grid or page template you choose for your page design. The grid is a conceptual layout device that organizes the page into columns and rows. You can impose a grid to provide visual consistency throughout your site. You can use the grid to enforce structure, but you also can break out of the grid to provide variety and highlight important information. Web pages that respect the grid and consistently align different elements have a more polished look than pages that have scattered alignments.
The World Health Organization Web site main page (www.who.int) in Figure 2-9 has a strong four-column grid. All of the text and graphic elements on the page align within the grid to create an orderly layout. Most current Web sites use tables in one form or another to give their pages structure and consistency. With table borders turned off, the user cannot tell the layout is held together by a table; they see a coherent, well-structured page. The reliance on tables as a design tool will eventually wane as more users adopt newer browsers that support CSS, which allows columnar positioning without tables.