XML stands for eXtensible Markup Language
XML is a markup language like HTML
XML was designed to store and transport data
XML is designed to describe yourself
Basically, XML is used to design the layout.
All UI and layout of your application is designed using xml.
Unlike Java (ie the Back Bone of your application), xml help you design your application ..
In addition, XML is also used to parse the data either from the database or server to your android apps.
The Difference Between XML and HTML
XML and HTML are designed with different goals:
XML was designed to carry data with their focus on what data ..
HTML was designed to display data with a focus on how data looks .. XML tag is defined as an HTML tag
XML Not Using Predefined Tag.
XML language has no predefined tags.
Tag in the example below
(like <to> and <from>) are not defined in any XML standard. These tags are “invented” by the author of the XML document.
HTML work with predefined tags such as <p>, <h1>, <table> , etc.
With XML, authors must specify the tags and structure of the document.
Source: MasterAndroid (App)