To get the most use out of CSS it is useful to review two html tags you may not have used much,
<span></span> and <div></div>
For example we can identify next paragraph because it is enclosed in div tags.
(If you view the html source code for this page you can see these tags)
Unlike most tags div and span tags by themselves do not do anything specific.
However they are very useful when combined with javascript or css.
For example the next paragraph is enclosed in div tags and has a different style applied to just that div.
Exercise
Build a page with several bits of text enclosed either div or span tags and view them in your browser
Now adjust the div tags and span tags by adding the following,
<div style='background-color:tan;'>some text</div>