Machine learning is an extremely broad field, and these days, applications can be found across areas that include web and mobile applications, the Internet of Things and sensor networks, financial services, healthcare, and various scientific fields, to name just a few.
Therefore, the range of data available for potential use in machine learning is enormous. In this book, we will focus mostly on business applications. In this context, the data available often consists of data internal to an organization (such as transactional data for a financial services company) as well as external data sources (such as financial asset price data for the same financial services company).
For example, you'll recall from Chapter 3, Designing a Machine Learning System, that the main internal source of data for our hypothetical internet business, Movie Stream, consists of data...
