ordred and descriptive List

HTML lists allow web developers to group a set of related items in lists.

ordered list with <ol>, <li> element

The HTML <ol> element is for grouping a collection of items that have a numerical ordering.
ordered-list items have type attribute whose values are 1, A, a, I, i and default is 1

        <ol>
            <li>item 1</li>
            <li>item 2</li>
        </ol>

  1. item 1
  2. item 2
  1. item 1
  2. item 2


descriptive list with <dl>, <dt>, <dd> element

The HTML <dl> element represents a description list.
The element encloses a list of groups of terms <dt> and descriptions <dl>
Common uses for this element are to implement a glossary or to display metadata 

        <dl>
            <dt>term</dt>
                <dd>description</dd>
        </dl>

HTML
- markup language for web document
CSS
- styling sheet for web document