This document discusses big data, including its scale and growth, characteristics, and applications. Some key points: - The digital universe now contains over 2.7 zettabytes of data that is growing exponentially from sources like social media, sensors, and mobile devices. - Big data has the characteristics of volume, velocity, and variety. It requires new techniques and tools to handle its large, diverse, and fast-changing nature. - Areas that use big data analytics include healthcare, retail, manufacturing, and homeland security to gain insights, improve decisions, and increase efficiency and revenue. - Technologies like Hadoop, NoSQL databases, and analytic databases are commonly used to manage and analyze big data at large