This document discusses startups, lean startup methodology, big data, and data science. It defines startups and describes lean startup culture. Big data is defined as the exponential growth of data in our lives due to technology advances. The 4 V's of big data are described. Data science involves statistical analysis, data mining, and predictive modeling to answer different types of questions. A/B testing is discussed as a way to test hypotheses and improve products. The document provides an overview of the data science field and skills required.