Xml basics (1), xml basics (

Xml basics (1), xml basics (
1. Introduction 1. Concepts

EXtensible Markup Language, a subset of Standard Generic Markup languages, is a Markup Language used to mark electronic files so that they have a structure, similar to HTML.
It can be used to mark data and define data types. It is a source language that allows users to define their own markup language.

It is designed to transmit data rather than display data. Its labels are not predefined and need to be customized. It is designed to be self-descriptive; it is a W3C recommendation standard and is very suitable for World Wide Web transmission. It provides a unified way to describe and exchange structured data independent of applications or vendors.

2. Analysis

XML is only plain text
XML is nothing special. It is just plain text. Any software capable of processing plain text can process XML.

However, applications that can read XML can process XML tags in a targeted manner.

The functional meaning of a tag depends on the characteristics of the application.

Ii. Purpose

1. XML separates data from HTML. If you need to display dynamic data in HTML documents, it will take a lot of time to edit HTML whenever the data changes.
With XML, data can be stored in an independent XML file. In this way, you can focus on HTML layout and display, and make sure that you do not need to make any changes to HTML to modify the underlying data.
By using several lines of JavaScript, you can read an external XML file and update the data content in HTML.

2. XML simplifies data sharing between incompatible systems and transfers data in the real world. computer systems and data are stored in incompatible formats.
XML data is stored in plain text format. Therefore, a data storage method independent of software and hardware is provided, and data can be easily exchanged between incompatible systems.
This makes it easier to create data that can be shared by different applications, because data can be read through a variety of incompatible applications, data exchange with XML reduces the complexity of data exchange between incompatible systems. This makes it easier for XML to expand or upgrade to a new operating system, application, or browser without losing data.

3. XML makes your data more useful Because XML is independent of hardware, software, and applications. XML makes your data more available and useful.
Different applications can access your data, not only on HTML pages, but also from XML data sources.
With XML, your data can be used by a variety of reading devices (handheld computers, voice devices, news readers, etc.), and for blind or other persons with disabilities.

Many new Internet languages are created using XML:
XHTML-Latest HTML Version
WSDL-used to describe available web Services
WAP and WML-markup language for handheld devices
RSS-language for RSS feed
RDF and OWL-used to describe resources and Ontology
SMIL-used to describe web-targeted multimedia

Iii. Comparison with HTML 1. XML is not an alternative to HTML, and XML is a supplement to HTML.

XML does not replace HTML. It is important to understand this. In most web applications, XML is used to transmit data, while HTML is used to format and display data.

The best description of XML is that XML is an information transmission tool independent of software and hardware.

2. XML and HTML are designed for different purposes.

HTML is designed to display information, while XML is designed to transmit information. HTML is designed to display data. Its focus is on the appearance of the data. XML is designed to transmit and store data, with the focus on data content.

3. XML allows creators to define their own labels and their own document structures.

You can use XML to create your own tags. The tags used in HTML (and the HTML structure) are predefined. HTML documents only use tags defined in HTML standards (such as <p> and

Related learning: XML Learning