In HTML, for example, the
h1
element is a semantic element, which gives the text it wraps around the role (or meaning) of "a top level heading on your page."
<
h1
>
This is a top level heading
</
h1
>
By default, most browser's
user agent stylesheet
will style an
h1
with a large font size to make it
look
like a heading (although you could style it to look like anything you wanted).
On the other hand, you could make any element
look
like a top level heading. Consider the following:
<
span
style
=
"
font-size
:
32px
;
margin
:
21px 0
;
"
>
Not a top-level heading!
</
span
>
This will render it to look like a top level heading, but it has no semantic value, so it will not get any extra benefits as described above. It is therefore a good idea to use the right HTML element for the right job.
HTML should be coded to represent the
data
that will be populated and not based on its default presentation styling. Presentation (how it should look), is the sole responsibility of
CSS
.
Some of the benefits from writing semantic markup are as follows:
- Search engines will consider its contents as important keywords to influence the page's search rankings (see
SEO
)
- Screen readers can use it as a signpost to help visually impaired users navigate a page
- Finding blocks of meaningful code is significantly easier than searching through endless
div
s with or without semantic or namespaced classes
- Suggests to the developer the type of data that will be populated
- Semantic naming mirrors proper custom element/component naming
When approaching which markup to use, ask yourself, "What element(s) best describe/represent the data that I'm going to populate?" For example, is it a list of data?; ordered, unordered?; is it an article with sections and an aside of related information?; does it list out definitions?; is it a figure or image that needs a caption?; should it have a header and a footer in addition to the global site-wide header and footer?; etc.