HTML and CSS Reference
In-Depth Information
The components of hypertext
HTML
is a language for describing hypertext documents. Hypertext
documents are made up of headings, paragraphs, bulleted lists, and,
importantly, links to other hypertext documents; it's the links that con-
stitute the
hyper
part of hypertext. In this section, we'll look at things
from the bottom up, starting with how an
HTML
document indicates
the existence of a paragraph or a heading before combining everything
to make a document. The following diagram shows the concepts that
make up
HTML
, from simple components on the left to complete docu-
ments on the right.
Tags, elements, and attributes
A
tag
is a bit of text that acts as a point demarcation. To create a tag,
HTML
gives certain characters special meaning: the angle brackets
<
and
>
.
Putting characters within angle brack-
ets creates a tag. You can see in this
diagram that there are two tags,
<h1>
and
</h1>
: a start tag and an end tag.
An end tag always matches a start tag,
except that it has a slash after the
opening angle bracket.
The combination of a start tag and an
end tag defines an
element
. Everything
between the two tags is referred to as
the
contents
of the element.
