History :• XML is designed to carry data, not to
• It has its roots in document
management and is derived from SGML
•It is officially recommended by W3C.
What is XML?
• XML means “Extensible Markup
Language”, is a markup language
much like “HTML”.
• It is designed to transport and
store data and a method for putting
structured data into a text file .
• Enables you to create and format your
own documents markup.
• The term markup refers to anything
that is not intended to be part of the
• The markup takes the form of tags
enclosed in angle brackets,<>.
What is SGML?
• SGML is a international standard for
defining descriptions of the structure
and content of different types of
• A universal language used to describe
thousands of different data types.
What is HTML?
• HTML is a “Hyper text Markup
language”, a specific language of SGML
used on World Wide Web.
HTML is for humans.
XML is for computers.
HTML describes web
XML describes data.
Tags and attributes are
predetermined and rigid.
You don’t want to see
error messages about the
web pages you visit.
Allows user to specify
what each tag and
The rules are strict and
errors are not allowed, in
this way XML is like a
XML Facts:• important because it removes two
constraints which were holding back
• Dependence on a single, inflexible
document type (HTML).
• The complexity of full SGML, whose
syntax allows many powerful but
Documents Schema:• Document type definition(DTD)
• XML Schema
Querying and transformation
•FLWOR E expressions
•Sorting of Results
•Functions and Types
Application Program Interfaces
• Document Object Model(DOM)
• Simple API for XML(SAX)
• Storage of XML Data
Storage of XML Data:•Non -relational Data Stores
• Relational Databases
•Store as String
•Map to relations
•Publishing and Shredding XML Data
• Storing data with Complex Structure
• Standardized Data Exchange Formats
• Data Meditation
• Self Documenting
• Makes your data more available
• Nested Structure
• Simplifies Platform Changes
•Simplifies Data Transport
•Simplifies data sharing
XML Syntax rules
• All XML elements must have a closing tags
• XML Tags are case sensitive
• XML Elements must be properly nested
• XML documents must have a Root