Guided Notes
Introduction to XML
Elements, attributes, and self-describing data.
XML (eXtensible Markup Language) structures data using custom, nested tags you define yourself — unlike HTML's fixed set of tags, XML lets you name elements to match your data: <book><title>...</title></book>.
Every element must be properly closed and nested — a document that follows these rules is called 'well-formed.' Attributes add extra detail to an element: <book id="42">.
XML is still widely used for data exchange between systems (SOAP APIs, configuration files, some data feeds) even though JSON has replaced it in most new web APIs.