This document provides an overview of big data, including its definition, characteristics, sources, tools, applications, risks, benefits and future. Big data is characterized by its volume, velocity and variety. It is generated from sources like users, applications, sensors and more. Tools like Hadoop and databases are used to store, process and analyze big data. Big data analytics can provide benefits across many industries and applications. However, it also poses risks around privacy, costs and skills that must be addressed. The future of big data is promising, with the market expected to grow significantly in the coming years.