Once your HTML files are ready, you need to provide a way for the user to navigate them. You might think of this as binding a loose collection of pages into a book. HTML Help provides three main navigation interfaces:
A table of contents (TOC). The table of contents is useful for providing an overview of your content, especially for novice users.
A keyword index. A good index lets the reader search for a word using a synonym (for example, "settings" or "preferences"), a phrase, or even an inverted phrase (such as "creating pages" or "pages, creating"). Usability studies show that most users prefer using the keyword index.
Full text search (FTS). Advanced users often prefer using full-text search, just as they do on the web.