XML: structured documents with explicit markup
Learn elements, attributes, namespaces, and schemas so XML-based standards stop looking like walls of angle brackets.
Why this matters
XML remains important in geospatial standards, configuration, data exchange, and schema-driven systems. The syntax is different from JSON, but the same basic questions still matter: what structure is allowed and what does each value mean?
Learn it
XML represents information with nested elements and optional attributes. Namespaces let multiple vocabularies coexist without name collisions. XML Schema can define allowed elements, types, cardinality, and constraints. Whitespace and ordering can matter depending on the specification. The standard that uses XML—not XML itself—defines the business or geospatial meaning.
Work through an example
A sensor reading might be an element with attributes for units and a child timestamp. Another standard could represent the same concepts differently while still using XML.
<observation units="C">
<value>18.4</value>
<time>2026-09-30T17:00:00Z</time>
</observation>Practice
- 1Identify the root element, child elements, and attributes in the sample.
- 2Add a namespace prefix and explain why a namespace exists.
- 3Compare the information with the JSON lesson and separate syntax from meaning.
What to watch for
Do not treat an XML tag name as universally meaningful. Always interpret it in the specification and namespace that define it.
Where this takes you
XML literacy helps with KML, schemas, geospatial standards, configuration, and many mature integration formats.