XML stands for Extensible Markup Language and is used as a set of encoding rules that can be read by both humans and machines. While similar to HTML, XML was not designed to describe data but transport and store it. HTML focuses on what the data looks like not what the data is, unlike XML. The tags used in XML are not pre-defined, and must be defined by the user, therefore allowing for it to be more specific, as it’s purpose is to store information and self-defined tags allow for that information to be more instructive. XML cannot be used without a piece of software or hardware to receive or display it.
Many different applications, programmes and sites use XML, as it can be manipulated to fit specific needs. XML is becoming particularly more important in electronic publishing, as it allows for e-books to carry extra information that allows for them to exist in a number of different formats such as MOBI, EPUB and PDF files. This means that an e-book using XML can be used by a variety of e-reading platforms such as the Amazon Kindle, Nook, and Apple iPad. The ability to use self-defined tags means that information within the file such as the author or publisher can have their own tags without causing any confusion. For example:
<title>The Fault in Our Stars </title>
The fact that XML can be used across a variety of systems means that the information will be safe despite any changes to software and hardware, allowing for the data to survive throughout the evolution of technology.