Bold type (or boldface) is a form of type that is made to stand out by making the letters thicker and heavier. It is often used in headings or for emphasis, and sometimes used where italic type should be used instead.
Bold type can be produced in HTML by use of the <b> and <strong> tags (the former tag has been deprecated in more recent version of HTML and completely removed from XHTML in favor of the latter). Bold is achieved in CSS by use of font-weight: bold.