Style sheets provide a way to define a full array of layout specifications for HTML topics such as font style and size, line spacing, paragraph indents, and more. Similar to templates used by Microsoft Word and other programs, a style sheet is a template that controls the formatting of topics. You can alter the appearance of a topic by changing the formatting assigned to it from a style sheet.
Style sheets enable you to maintain consistency among your topics. You can share them with other authors so your projects have a familiar look and follow your company's design standards. In addition to attaching topics to style sheets, you can also assign styles within topics and reuse them (embedded styles) and assign styles to paragraphs and characters within topics on an individual basis (inline styles).
There are three ways to work with style sheets and styles:
External style sheets: Style definitions are stored in a style sheet file (.CSS) that is separate from the topics that use it. A single style sheet can be linked to any number of topics. The individual styles that are defined in the style sheet are available to all topics that use the style sheet. When you modify a style, all topics that are linked to the style sheet are automatically updated.
Embedded styles: Style definitions are embedded (saved) in an individual topic file (.HTM). If the file is linked to a style sheet, all embedded styles override the styles in the style sheet that are applied to the text.
Inline styles: A block of text within a single topic is formatted directly in the WYSIWYG Editor. If the file is linked to a style sheet, all inline styles override styles in the style sheet and any embedded styles that may have been saved within the file as well.
Note: There is a hierarchy among these styles when they are used in combination. For details, see About cascading style sheets.