There are 3 basic types of lists, 'OL', 'UL', and 'DL'.
OL stands for Ordered List, where the list is numbered.
UL stands for Unordered List, where the list is bulleted.
DL stands for Definition List, where there is a term and then an indented definition.

Both the 'OL' and the 'UL' lists are shaped like this:

<Open list> .... either <ol> or <ul>
<li> list item 1 </li>
<li> list item 2 </li>
</Close list> .... either </ol> or </ul>

The Definition list has two parts, a term <dt> and a defintion <dd>:

<dl> ...opens the definition list
<dt> definition term</dt> <dd> definition definition </dd>
</dl>

Examples:

Ordered: 
Unordered: 
HTML Source What you see HTML Source What you see
<ol>
<li>One</li>
<li>Two</li>
<li>Three</li>
</ol>
  1. One
  2. Two
  3. Three
 <ul>
<li>One</li>
<li>Two</li>
<li>Three</li>
</ul>
  • One
  • Two
  • Three
Definition: 
HTML Source What you see
<dl>
<dt>Term1</dt> <dd>definition1</dd>
<dt>Term2</dt><dd>definition2</dd>
<dt>Term3</dt> <dd>definition3</dd>
</dl>
Term 1
definition 1
Term 2
definition 2
Term 3
definition 3