This document provides an introduction to big data and data science. It defines big data as large and complex datasets that cannot be processed by traditional software. Big data comes from various sources like mobile devices, IoT, social media, and more. Data science is the process of extracting knowledge from raw data through techniques like machine learning. The document outlines the data-to-knowledge process and popular tools used in data science like Hadoop, Spark, Python libraries Scikit-Learn and Keras. It also discusses how big data is important in applications like healthcare, predicting hospital admissions, and improving telehealth services.