Semi-structured data fits in between unstructured. It can be considered a type of structured data, but lacks the strict data model structure. JSON is a form of semi-structured data. While good JSON will have a defined format, there is no specific schema for data that is always strictly enforced. Much of the time, the data will be in a repeatable pattern that can be easily converted into structured data types like the pandas DataFrame, but the process may need some guidance from you to specify or coerce data types.