examples of semi structured data ?
JSON and XML are not tools. They are data formats. For example, to find out more about JSON you can look up the RFC description that specifies how to format JSON files:

https://tools.ietf.org/html/rfc7159

It explains how to tag the data. Then there are tools that validate JSON, and XML files to see if they conform to the requirements, or there are tools that convert JSON into another format or read it into memory into some object or class.