In HTML-based Help projects, each .HTM file represents one topic. Topics are saved in HTML format and can include text, images, hyperlinks, bookmarks, multimedia, ActiveX controls, Dynamic HTML, link controls, etc. Topics have a topic title and a file name, which are identical by default but do not have to be the same. Also, in order for the topic contents to automatically synchronize with the Contents on the left side of the viewer, the topic file names need to use underscores rather than spaces. For more information, see Saving file names with underscores.
HTML-based Help uses a book and page metaphor to represent topic categories in the table of contents. This kind of page references a topic in the Help system. When users click the page from the Contents tab in the viewer, its corresponding topic is displayed in the right-hand viewing pane. Users can also access topics by using the Index tab, browse buttons, related topics buttons, hyperlinks inside topics, and the Search tab.
After you create a new topic file and assign a title to it, the topic is added to a database that is maintained for your project behind the scenes. The topic is automatically assigned a status of "In Progress" when it is created. You can change the status at any time, if you want to manage authoring tasks.