This document introduces cloud computing and discusses its fundamentals. It begins by explaining what cloud computing is and discussing its history and evolution from early concepts of time-sharing to modern cloud platforms. It then outlines the key characteristics of cloud computing like on-demand access, resource pooling, and measured service. The document also describes the major cloud deployment models including public, private, hybrid and community clouds. Finally, it discusses how traditional data centers evolved into private clouds through increased virtualization and automation.