The tags 'bold' and 'strong' make the enclosed text bold, whilst 'italics' and 'emphasis' italicise the enclosed text. Used to emphasize important keywords and phrases to help search engines and human visitors identify the main topic of that page. This can lead to higher rankings for those terms. Overview:
- "Strong is treated the same as bold, italic is treated the same as emphasis" . . . Matt Cutts July 2006
- Bold text is given more weight than ordinary text. Italic tag is therefore also more important than ordinary text.
- The difference between using header tags and strong/bold/italic tags is that header tags should be used to emphasize the main topics and logically break content into different sections while other text-modifying tags are not meant to carry any semantic meaning. These tags are just presentational elements.
- Using your keywords throughout the page, it’s helpful to put them into italics, bold, strong or emphasis to make sure the search engines know that these words are important.
- Bold and italic are a way to emphasize a word or a couple of words that are important. Search engines read the <b> and <i> text and get the idea that what is in bold and/or italic is more important than the rest of the text. The same applies to <strong> and <em>.