6.2 Types of Data

Data comes in different shapes. Structured data fits neatly in tables (like a spreadsheet of names and ages), while unstructured data — photos, audio, free text — has no fixed rows and columns.

Within tables, values are either numeric (numbers you can measure, like price) or categorical (labels like region or 'yes/no'). Knowing the type tells you how to clean, visualize, and model it.

A merchant's sales sheet is structured (date, item, birr amount). The customer photos they post on Telegram are unstructured. Within the sheet, 'birr amount' is numeric and 'payment method' is categorical.