This document discusses virtualization and cloud computing, specifically hybrid cloud architectures. It defines hybrid cloud as a cloud computing environment where an organization provides and manages some resources in-house and has others provided externally from a public cloud provider. The document outlines the key considerations for hybrid cloud planning, examines hybrid cloud architecture which combines a private cloud with at least one public cloud, and discusses the advantages of cost efficiency, isolation, availability and flexibility as well as the disadvantages of data beyond the firewall and greater internal IT maintenance required.