You've been reading about what great HTML code Dreamweaver writes, and how all you hand coders need to get on the WYSIWYG bandwagon. But there are exceptions to every rule. In the process of formatting text, deleting elements, and—in general—building a Web page, it's quite possible to end up with less-than-optimal HTML coding. While Dreamweaver usually catches potentially sloppy HTML, you may nonetheless run across instances of empty tags, redundant tags, and nested tags in your Dreamweaver pages.
For example, in the normal course of adding, editing, and deleting content on a page (either by hand or even in Dreamweaver's Design view), you can occasionally end up with code like this:
<div align="center"> </div>
This empty tag doesn't serve any purpose and only adds unnecessary code to your page. Remember, the less code your page uses, the faster it loads. Eliminating redundant tags can improve the download speed of your site.
Another possible source of errors is you. When you type HTML in Code view or open pages created by another program, you may introduce errors that you'll need to clean up later.
Aware of its own limitations (and yours), Dreamweaver ...