Digital Lexicon Hub

A text-based markup language for representing structured information with custom elements and hierarchical relationships.

XML remains the exchange format behind many sitemaps, RSS feeds, SOAP services, e-invoicing standards and enterprise integrations, so teams that understand it can scope integration work and data mapping more accurately.

A distributor publishes a product feed as an XML file validated against an XSD schema, so a marketplace can reject records with a missing or a non-numeric before importing 12,000 listings.

XML is verbose and slower to parse than compact formats such as JSON, and a well-formed document is not automatically valid against a schema. Parsers that resolve external entities can be exposed to XXE attacks if not hardened.

An XML document consists of nested elements delimited by start and end tags, with attributes, text content and an optional declaration that sets version and encoding. A document is well-formed when it follows the syntax rules, such as one root element and properly nested tags, and valid when it also conforms to a DTD or XML Schema. Namespaces prevent name collisions, and tools such as XPath and XSLT query and transform the tree.