To ensure that assistive software and robots understand the content and context of the page it is important to lay it out in a logical fashion.This section of tutorials explains the importance of using appropriate structural (semantic) codes so that blind users can gain an initial overview of the page and its' structure. These semantic codes are also used by search robots, such as Google, and academic research tools, so their correct application helps all web users.
Although it sounds technical, using proper semantics is really quite simple and logical. The idea is that the semantic codes, such as headings, paragraphs, list items, labels and legends provide the basic skeleton of the page structure. They mark up individual pieces of text and explain how they all fit together as a logical story.
Another advantage of using these semantic codes is that you can design your own style for each and thereby easily maintain a consistent look to your site. One word of warning though - only use these codes for structuring your content. Do not use them to make the page look pretty. Some of these codes are stored by assistive software in a small memory cache to help the user. If you use a heading code to format a paragraph of text you can easily fill the users cache and cause the browser to crash.