| HyperText | Refers to links that connect web pages to one another. |
| WWW | World Wide Web. |
| Tags | The element name surrounded by < and >. The name of an element inside a tag is case-insensitive. |
| Attributes | Additional values that configure the elements or adjust their behavior in various ways. |
| Inline-level | Occupies only the space bounded by the tags that define it. |
| Block-level | Occupies the entire space of its parent element (container), thereby creating a "block box". |
| Opening tag | Name of the element, wrapped in opening and closing angle brackets: <p>. This states where the element begins or starts to take effect. |
| Closing tag | The same as the opening tag, except that it includes a forward slash before the element name: </p>. This states where the element ends. |
| Content | The content of the element. <p> I'm content </p> |
| Element | The opening tag, the closing tag, and the content together comprise the element. <p> I, the content, together with the two tags that enclose me, form an element </p> |
| Nesting elements | Put elements inside other elements. <p> Paragraph tag with a <b>bold tag</b> inside </p> |
| Void elements | Some elements have no content and are called void elements. <img src="./favicon.ico" alt="Image tag without content and closing tag" /> |