Heading styles are more than just a way to make your text different sizes. Headings are used to define a hierarchy of subjects in your document. Also, headings are used by the programs that index web pages in order to add your web page to their database. Spiders crawl around on the web looking for web pages. When a spider finds a web page, it indexes that web page into the search engine's database.
Terms used in headings are excellent fodder for creating a database entry.
Bold, Italic, Underline Bold, italic, underline styles are used on the web, just as they are used in your word processor. Hyperlinks are always underlined, so this might result in some confusion if you use underlining much in your document. Images Images have their very own tag. This code and syntax is borrowed from UNIX-based operating systems. One reason might be that a user is surfing the web with images turned off in his or her browser.