Structured data refers to the kinds of data with a high level of organization, such as information in a relational database. It often prescribes to a data type such as date, address, numeric values, categorical attribution stored in a pre-defined field. 

Signals leverage automated machine learning to analyze each and every structured dimension in your data and automatically provides statistics and visualization for analysis.  You can simply visualize the Structured Data by adding them to a Widget. 

Here is how: "How to create a widget (visualization)"