This document introduces big data by defining it as large, diverse data that requires new techniques to extract value from. It notes that big data comes from many sources like sensors, social media, purchases, and cell phones. Big data is characterized by its scale (volume), complexity (variety), and speed (velocity). It provides examples of how big data is used for personalized promotions and healthcare monitoring. Finally, it outlines how much data companies like Google, Facebook, and eBay process daily and yearly, demonstrating how big data is everywhere and can increase productivity and sales.