Formatting tags can be very useful when writing HTML and are more specific than creating general CSS classes for HTML elements. Formatting tags are primarily for modifying the way text appears. We can make the text bold, in italics, or even define them as a superscript or a subscript. There are a whole bunch of these, so we will just focus on a few of the most often used formatting tags. These tags are just like any other HTML element in that they have closing and starting tags.

Example

<p>
  <b>I am bold</b>
  <i>I am in italics</i>
  <sub>Last</sub>, but not <sup>least</sup>
</p>

Result

I am bold I am in italics _Last, but not ^least

While these formatting tags don’t make any major changes, it is nice to use them to accent text to help users understand your point. Like I said, there are quite a few of these, but the vast majority are never used anywhere because custom CSS classes have taken over. Basically, try to stick to only using these four formatting tags, unless you absolutely need to use another formatting tag. Also, you should research these tags before using them as some of them are going to become extinct with HTML5.