This document provides an overview of big data. It begins with an introduction that defines big data as massive, complex data sets from various sources that are growing rapidly in volume and variety. It then discusses the brief history of big data and provides definitions, describing big data as data that is too large and complex for traditional data management tools. The document outlines key aspects of big data including the sources, types, applications, and characteristics. It discusses how big data is used in business intelligence to help companies make better decisions. Finally, it describes the key aspects a big data platform must address such as handling different data types, large volumes, and analytics.