Qualitative vs. quantitative data
Watch the YouTube video on Symbolizing Map Layers || Qualitative data versus quantitative data for an introduction on the topic.
Further watch the YouTube video on Spatial Data And Qualitative Maps (from 14:54 to 28:49) by Lynn Songer, to understand how to visualize qualitative data.
Regarding quantitative data, things get more complex because quantitative data can be measured, can be summarized using statistical indices, can be classified etc.
The entry Measurement systems—values and what they represent at the ESRI ArcGIS Pro help page, introduces the measurements systems of spatial data whether qualitative or quantitative, while the presentations Levels of Measurement and Interpolation can be used as a reference (see course materials)
More advanced topics on quantitative data are dealt with in the chapters on Statistical Maps (Chapter 5) and on Spatial Interpolation (Chapter 14) of the online compilation of lecture notes of the course Intro to GIS and Spatial Analysis by Manuel Gimond (2024) to get an idea of the statistics used on quantitative spatial data. The work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License. A short presentation on Interpolation is also available at course materials.