This document provides an introduction to data science, including what it is, how the field has emerged due to big data, and the roles and skills of data scientists. It discusses how data scientists at LinkedIn used data analysis to improve their product's user connections feature. The data science process of framing questions, collecting and processing data, exploring for patterns, and communicating results is also outlined. Finally, the document discusses tools used in data science like SQL, data visualization software, and machine learning algorithms.