F# is a multi-paradigm programming language that encompasses object-oriented, imperative, and functional programming language properties. Now adopted in a wide range of application areas and is supported both by industry-leading companies who provide professional tools and by an active open community, F# is rapidly gaining popularity as it emerges in digital music advertising, creating music-focused ads for Spotify, Pandora, Shazam, and anywhere on the web. This book will guide you through the basics and will then help you master F#. The book starts by explaining how to use F# with Visual Studio, file ordering, and the differences between F# and C# in terms of usage. It moves on to explain the functional core of F# such as data types, type declarations, immutability, strong type interference, pattern matching, records, F# data structures, sequence expressions, and lazy evaluation. Next, the book takes you through imperative and asynchronous programming, F# type providers, applications, and testing in F#. Finally, we look into using F# with distributed programming and using F# as a suitable language for data science. In short, this book will help you learn F# for real-world applications and increase your productivity with functional programming.