Re: xml vs xhtml

by "Ted Temer" <temer(at)c-zone.net>

 Date:  Thu, 10 May 2001 10:05:36 -0700
 To:  "HWGBASICS" <hwg-basics(at)hwg.org>
 References:  vartec
  todo: View Thread, Original
Julie:

Here are some direct quotes. They came from:
http://whatis.techtarget.com/definition/


XHTML
As the World Wide Web Consortium (W3C) describes it, XHTML (Extensible
Hypertext Markup Language) is "a reformulation of HTML 4.0 as an application
of the Extensible Markup Language (XML)." For readers unacquainted with
either term, HTML is the set of codes (that's the "markup language") that a
writer puts into a document to make it displayable on the World Wide Web.
HTML 4 is the current version of it. XML is a structured set of rules for
how one might define any kind of data to be shared on the Web. It's called
an "extensible" markup language because anyone can invent a particular set
of markup for a particular purpose and as long as everyone uses it (the
writer and an application program at the receiver's end), it can be adapted
and used for many purposes - including, as it happens, describing the
appearance of a Web page. That being the case, it seemed desirable to
reframe HTML in terms of XML. The result is XHTML, a particular application
of XML for "expressing" Web pages.
XHTML is, in fact, the follow-on version of HTML 4. You could think of it as
HTML 5, except that it is called XHTML 1.0. In XHTML, all HTML 4 markup
elements and attributes (the language of HTML) will continue to be
supported. Unlike HTML, however, XHTML can be extended by anyone that uses
it. New elements and attributes can be defined and added to those that
already exist, making possible new ways to embed content and programming in
a Web page. In appearance, an XHTML file looks like a somewhat more
elaborate HTML file.



XML

XML (Extensible Markup Language) is a flexible way to create common
information formats and share both the format and the data on the World Wide
Web, intranets, and elsewhere. For example, computer makers might agree on a
standard or common way to describe the information about a computer product
(processor speed, memory size, and so forth) and then describe the product
information format with XML. Such a standard way of describing data would
enable a user to send an intelligent agent (a program) to each computer
maker's Web site, gather data, and then make a valid comparison. XML can be
used by any individual or group of individuals or companies that wants to
share information in a consistent way.
XML, a formal recommendation from the World Wide Web Consortium (W3C), is
similar to the language of today's Web pages, the Hypertext Markup Language
(HTML). Both XML and HTML contain markup symbols to describe the contents of
a page or file. HTML, however, describes the content of a Web page (mainly
text and graphic images) only in terms of how it is to be displayed and
interacted with. For example, the letter "p" placed within markup tags
starts a new paragraph. XML describes the content in terms of what data is
being described. For example, the word "phonenum" placed within markup tags
could indicate that the data that followed was a phone number. This means
that an XML file can be processed purely as data by a program or it can be
stored with similar data on another computer or, like an HTML file, that it
can be displayed. For example, depending on how the application in the
receiving computer wanted to handle the phone number, it could be stored,
displayed, or dialed.

XML is "extensible" because, unlike HTML, the markup symbols are unlimited
and self-defining. XML is actually a simpler and easier-to-use subset of the
Standard Generalized Markup Language (SGML), the standard for how to create
a document structure. It is expected that HTML and XML will be used together
in many Web applications. XML markup, for example, may appear within an HTML
page.

Early applications of XML include Microsoft's Channel Definition Format
(CDF), which describes a channel, a portion of a Web site that has been
downloaded to your hard disk and is then is updated periodically as
information changes. A specific CDF file contains data that specifies an
initial Web page and how frequently it is updated. Another early application
is ChartWare, which uses XML as a way to describe medical charts so that
they can be shared by doctors. Applications related to banking, e-commerce
ordering, personal preference profiles, purchase orders, litigation
documents, part lists, and many others are anticipated.

>>>>>>UNQUOTE<<<<<<

As you might suspect, there is a tad of disagreement, discussion and
argument connected with them. Is one better than the other?? I would think
that is an unfair question. I see them as two separate gizmos, each able to
do similar things but in slightly different ways.

Take two weeks off from work, stock up on gallons of coffee and several
dozen dough nuts. A little web surfing, (I simply typed in XHTML and XML in
the address line of IE-5), will give you reams of text on both subjects.

When you are done, maybe you could explain it to the rest of us.

Best wishes
Ted Temer
Temercraft Designs Redding, CA
temer(at)c-zone.net
www.temercraft.com/novels/
www.newsredding.com/
www.ramac-rc.org/




> Dear fellow list members,
>
> I know I am showing my ignorance with this question - but here goes:
>
> What is the difference between XML and XHTML?
>
> Thanks,
>
> Julie
>

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