XML stands for extensible markup language

- standardized way to describe documents and data

- text-based format

- can be easily transported via standard internet protocol.

- It based on SGML

- it became the W3C standard for data exchange in 1998 which is a result of combining the feature of SGML and HTML

SGML – standard generalized mark up language

-         create by IBM in 1974 for document sharing

-         became an ISO standard in 1986

-         HTML was its first popular adaptation

Why XML?

-         HTML and SGML cannot describe data. There is no easy way to extract data from it

-         The need to exchange data using the web as a data delivery mechanism