Tag rules (also called element rules) are CSS rules that are applied to any content that has been
marked with that particular HTML tag. For example, to make all Heading 1 text look bold and pink,
create a CSS tag rule for the h1 tag.
Class rules are CSS rules that are applied to any content that has been marked with that class
name. For example, to make the club name italic and bold everywhere that the club name is used in
a paragraph, create a class rule and apply that class rule to all the club names.
ID rules are CSS rules that are applied to any content that has been marked with that ID name.
This is similar to a class rules, except that ID rules can only be applied to one item per page.