XML vs. JSON

When two systems exchange data, they have to agree on how that data is written down. Two text formats dominate: one wraps every value in named tags (XML), and one writes values as key and value pairs (JSON).

Both are readable by people and parseable by machines. They differ in how much they weigh, what they can describe, and where you will actually meet them.

XML

XML stands for eXtensible Markup Language. It describes data as a tree of elements, where every element has an opening tag, a closing tag, and optional attributes.

<person>
  <name>John Doe</name>
  <age>30</age>