XML (eXtensible Markup Language) is a widely adopted standard created by the World Wide Web Consortium (W3C) in 1998. It is designed to store and transport structured data across different systems, regardless of platform or programming language. XML has become a foundational technology for applications that rely on data interchange, such as web services (e.g., SOAP), RSS feeds, and configuration settings.
Extensibility: Users can create their own tags suited to their application’s data needs.
Self-descriptive: Data is stored with metadata (tags), providing context.
Platform-independent: Can be used across different operating systems and programming environments.
Supports Unicode: Suitable for international use and multiple languages.
An XML document consists of elements enclosed in tags. Here's an example:
<book>
<title>Learning XML</title>
<author>Jane Smith</author>
<year>2025</year>
</book>
Web Services: XML is the basis for many APIs, especially SOAP-based services.
Configuration Files: Many applications (e.g., Maven, Android) use XML to define settings.
Data Interchange: Used in sectors like healthcare (HL7) and finance (FIX protocol).
Language-neutral data format
Easy integration with databases and other structured data formats
Extensively supported by tools and programming languages
Verbose compared to formats like JSON
Parsing can be slower
Not ideal for data storage or high-performance APIs
While XML offers more flexibility and features (like attributes, schemas, and namespaces), JSON has become more popular for web APIs due to its lighter weight and easier integration with JavaScript.