This document discusses different types of digital data including structured, unstructured, and semi-structured data. It provides examples and characteristics of each type of data. Structured data is organized in rows and columns like in databases and can be easily processed by computers. Unstructured data lacks a predefined structure or organization and makes up about 80% of organizational data. Semi-structured data has some structure but does not conform fully to predefined data models. The document also discusses big data in terms of its volume, velocity and variety characteristics as well as challenges in capturing, storing, managing and analyzing big data.