A data model (or datamodel) is a set of tables, linked by relationships and is an abstract model that organizes elements of data and standardizes how they relate to one another and to properties of the real world entities.
In computer science, a list or sequence is an abstract data type that represents a countable number of ordered values, where the same value may occur more than once.
In programming languages, a type system is a set of rules that assigns a property called type to the various constructs of a computer program, such as variables, expressions, functions or modules.
The World Wide Web Consortium (W3C) is the main international standards organization for the World Wide Web (abbreviated WWW or W3).
In computing, Extensible Markup Language (XML) is a markup language that defines a set of rules for encoding documents in a format that is both human-readable and machine-readable.
XML Information Set (XML Infoset) is a W3C specification describing an abstract data model of an XML document in terms of a set of information items.
XSD (XML Schema Definition), a recommendation of the World Wide Web Consortium (W3C), specifies how to formally describe the elements in an Extensible Markup Language (XML) document.
XPath (XML Path Language) is a query language for selecting nodes from an XML document.
XQuery (XML Query) is a query and functional programming language that queries and transforms collections of structured and unstructured data, usually in the form of XML, text and with vendor-specific extensions for other data formats (JSON, binary, etc.). The language is developed by the XML Query working group of the W3C.
XSLT (Extensible Stylesheet Language Transformations) is a language for transforming XML documents into other XML documents, or other formats such as HTML for web pages, plain text or XSL Formatting Objects, which may subsequently be converted to other formats, such as PDF, PostScript and PNG.