This document provides an overview of big data by exploring its definition, origins, characteristics and applications. It defines big data as large datasets that cannot be processed by traditional software tools due to size and complexity. The document traces the development of big data to the early 2000s and identifies the 3 V's of big data as volume, velocity and variety. It also discusses how big data is classified and the technologies used to analyze it. Finally, the document provides examples of domains where big data is utilized, such as social media, science, and retail, before concluding on the revolutionary potential of big data.