"Jonathan N. Little said:
Again, if you would learn the basics first before jumping in it would be
less confusing.
Semantic markup means to place text in elements that define the
structure of the document and not how it looks
Another way that you might think of the semantics of a mark up is that
it is a way to tell a browser how to make a basic presentation. This way
of looking at it can give you some immediate understanding of what is
good and what is bad markup.
If you turn off or omit all the styles that you, the author, have added,
or mean to add, you get a basic appearance. Never mind why for the
moment. The point is that browsers do not keel over and die because you
have not told it about appearances or presentation. There are no
browsers that have no ideas of their own how to present HTML.
Only non-existent browsers have no sense of style. Perhaps it could be
more charitably said that only abstract browsers (let's grant them
existence) have no sense of style. But non-existent browsers and
abstract browsers are almost completely useless browsers.
You will find that a lot of orthodox explanations of semantic markup
deal in this useless variety of browser. So, as a practical novice in
these matters, I suggest you have nothing at all to do with the orthodox
types of explanation, no matter that they are mostly true as far as they
go.
Now, if the browser basic appearance, without a skerrick of author
styles, makes no sense to a human being, then, if the browser is a
competent one, you have done a very bad job. You have done a really
first class job if your site is perfectly understandable on the HTML
processing by the browser.
Let me give you an example, you want to say something about trees. You
want people to know that what you have to say is about trees. One
obvious way to do this is to put a heading up.
<h1>Trees</h1>
that should be presented on its own as a first item, it would stand out
by being bold or big or loud or simply by being on its own with a pause
or space below it. The real life browsers, the ones that exist, know how
to present such a thing so that most basically educated people can
understand it. Real browsers transmit meaning by knowing *how to
present* text that is marked up in level one heading tags.
Below or after this would be various thoughts you want to say about
trees. Each thought, by long convention and evolution of communication,
is probably best put into paragraphs. Real browsers know how to present
these in ways that humans recognise. I don't know what abstract browsers
do, you will have to ask various folk who like to conjure them up.
I will stop now and hope you will take away at least the idea that if
you remove all *your* styles, how does your webpage look (or sound or
feel in non-visual browsers), crucially, does it make sense to a human?