What is XML? Complete Guide to XML Format
XML stands for Extensible Markup Language. It is a structured text format used to describe data with nested tags, attributes, and repeating elements. XML is older than JSON, but it is still widely used in feeds, enterprise systems, document workflows, and data exchange pipelines.
How XML Works
XML organizes data into elements. Each element has a start tag and end tag, and elements can contain text, attributes, or other elements. That makes XML well suited for hierarchical data.
<words>
<row>
<word>Tell</word>
<example>Tell me what these are.</example>
<meaning>告诉</meaning>
</row>
<row>
<word>These</word>
<example>These are cars.</example>
<meaning>这些</meaning>
</row>
</words>Main Parts of XML
Elements
Tags like `<row>` and `<word>` define the structure and meaning of the data.
Attributes
Extra metadata can be stored on tags, for example `<row id="1">`.
Nested Structure
Elements can contain child elements, which is why XML can represent more than flat tables.
Repeating Nodes
Repeating tags like multiple `<row>` entries often become rows during XML to CSV conversion.
Where XML Is Still Used
- Content feeds and document publishing pipelines
- Enterprise integrations and older business systems
- Configuration files and import/export workflows
- Structured records shared between tools that require explicit tagging
XML vs CSV
| Feature | XML | CSV |
|---|---|---|
| Structure | Hierarchical | Flat table |
| Readability | Verbose but explicit | Compact and spreadsheet-friendly |
| Best For | Tagged data exchange | Tabular editing and analysis |