Need a dummies explanation...

Potemkin

Hey there i am trying to find a newbie description of XML.

Everything I read describes it in technical terms like somthing about SGML.

Need clarification on:

SGML
XML
XHTML

One more thing is there a site that i can visit that will explain all the different languages and their uses, why to use them, like a whole break down of java, c ,c++, php, html etc..

planetsim

For your latter a search here and on Google will bring up a whole pile of results. However at the end of the day each language has its purpose.

SGML - I cant say much about it however HTML, XML, XHTML are based on it, I dont know enough about SGML to give a good explanation but you should again find one here.

XML - http://www.w3schools.com/xml/default.asp
XHTML - http://www.w3schools.com/xhtml/default.asp
HTML - http://www.w3schools.com/html/default.asp

If your just learning these you really should put PHP off until you have XHTML/HTML down tight as well as another scripting language Javascript and of course CSS

Weedpacket

http://xml.coverpages.org/xml.html (in particular, the first XML faq listed on its FAQs, i.e., this one).

And of course there is the ultimate reference, the W3C ( XML at http://www.w3.org/XML/ , (X)HTML at http://www.w3.org/MarkUp/#recommendations).

As for SGML: unless you've got a large corporation and you're trying to maintain corporate branding and documentation standards on everything from Annual Reports to business cards - I wouldn't bother 🙂

pohopo

In simple terms XML is a common way to transfer structured data (a table of data) between two sites/servers. With XML an ASP site can receive and send data to a JAVA site without any complicated configurations (relatively speaking here).

An example of XML use is where I call a site (ie a web service) and I tell that site I want a list of all their cars in blue, the site will then send me this list along with the price, make, and model of the cars in XML format. I will then take this XML formatted list and either display it on my site or insert it into my own databases.

Now you want to know how you can use this in your site and the answer is most likely you have no need for it. XML is huge in the corporate world where even in the same company you need to deal with different environments, but for a personal web site or small company site it does not have a whole lot of use.

planetsim

Well yes thats the idea of XML however, it doesnt need to be two or more sites interacting XML is bigger than just the web you can have say as much as I hate it. MS Excel with say a Java Application which inserts the data into the XML Document with a much nicer interface (of course thats an example I doubt such a program is out there).

XML at its core is just data tags explaining data this is the most simplist terms you can come with. At the end of the day XML will not make you a pretty layout, create an image for you (exception SVG) but it will explain data. Which then allows the transfer of data from one site to another without requiring access to a database or in software terms knowledge of how a program saves a file MS Office suite is one example now that has incoporated it.

Weedpacket

However, unlike tables of data, XML is capable of expressing arbitrarily complex structures (read: documents) without too many contortions (how would you represent an XML document like This insance of XHTML as table data?)