A master page layout used in document creation systems such as word processing, desktop publishing and the Web. The style sheet is a file that is used to store margins, tabs, fonts, headers, footers and other layout settings for a particular category of document. When a style sheet is selected, its format settings are applied to all the documents created under it, saving the page designer or programmer from redefining the same settings over and over again for each page. See Cascading Style Sheets, template and document.