With the advent of HTML5, the b and strong tags have once again become a part of the language. They had been removed in prior versions of HTML. In order to produce bold text, you now have 2 options depending upon the circumstances.

Screen readers require the strong tag in order to read text on a web page in a stronger way than other text on the page. If you wish to simply make the text appear bold on the page for visual readers, you use the tag.

The same approach is available for italic text, although italics are not used often on the web due to its poor readability. The em tag tells a screen reader to add emphasis to the word when it is being read to a user. The i tag simply makes the text look italic visually.

Different Dreamweaver versions set the specific tag differently when you choose the B or I in the Properties panel. Newer versions of Dreamweaver are targeting the HTML5 doctype, so the tag that is created using the B icon in the Properties panel can vary.

The Preferences area in Dreamweaver allows you to control which tag is being created by default. Go to Edit-> Preferences (Win) or Dreamweaver -> Preferences (Mac) and choose the General Category in the left column. Within the Editing options area the 5th option down allows you to choose whether you want the or created by default within Dreamweaver.

If you check that option under Editing options, you always have the tag created by Dreamweaver so all screen readers will read the text in a stronger way than standard text on the page. Earlier versions of Dreamweaver did not offer this option since HTML had dropped the use of the b and i tags.