subject: What the heck is XML? [print this page] What the heck is XML? What the heck is XML?
XML is an acronym for Extensible Markup Language and is also , as the name suggests, a markup language meant for methodized documentation.
A structured document is simply just about any document that has both equally content plus a description of precisely what the content is, by way of example is the particular content perhaps the title, the body or the footer of the document. This is certainly really quite crucial as content in the body can be very distinct in function coupled with meaning from content in the footer.
A markup language may serve as an easy way to see structures in a document, however the XML requirements sets a standard technique for putting mark-ups to documents.
Asking Yourself Does indeed XML Vary from Html?
Simply, both the tag semantics as well as the tag set are generally fixed in html dissimilar to with XML you don't have set tag set, as an example you might without difficulty have a tag set named , while | whilst in html there is no such tag set and for that reason it wouldn't be recognized.
By way of rapid modifications to the WWW in addition to by way of continual revenues of new and also improvements inside of recent browser sellers, the W3C is actually hoping to redefine and additionally lengthen the definition of HTML, however these alterations are invariably rigidly characterized and they must always be backward compatible.
XML having said that, doesn't aim to define or specify semantics or a tag set. For example, XML permits you the facility so that you can define tags along with the relationships between them. Due to the fact there's no definite tag set you simply can't have any preconceived semantics. Merely the software program which in turn processes the XML or a stylesheet definitely will specify the semantics of the XML document.
Is XML More Like SGML?
At some level absolutely yes, XML is usually a similar, however very much restrained type of SGML. SGML, short for Standard Generalized Markup Language, has been the standard with regard to keeping structured documentation for upwards of a decade. However as we know XML is centered on serving documents over the web, and SGML seriously isn't well suited for this at all.
There's also slight variations in the way documents are fully understood between xml and SGML, by way of example white spaces immediately next to tags are read differently.
Exactly why XML?
As mentioned before, XML was created generally allowing for your storage and transportation of richly structured documents over the world wide web. For reasons listed in this informative article already, HTML and SGML aren't actually well suited for the job.
HTML comes bound with a fixed set of semantics which isn't going to cater to arbitrary structures or tags.
SGML should support arbitrary structures however it's pricey and also tough to implement totally for a web browser.
Even so to think about XML overtaking along with changing SGML is a little unrealistic, SGML is actually effective in business oriented applications and in reality lots of businesses simply filter SGML to XML for web browser utilization.
