Virtualization brought unprecedented cost reduction and agility to IT infrastructure - decimating hardware manufacturers on its path. IBM, for example, is shrinking for 4+ years in a row because of it. I first heard of VMWare about 7 years ago working on data center migration. Didn't make big impression. That all changed with Cloud, but didn't make clear connection with Virtualization until this book. Four key areas - CPU, Memory, Storage, Network. Also, Virtual Machine and Containers. This book was a great intro - rather repetitive, but explains the concept without being too technical.