Cloud computing can be defined as the use of new or existing computing hardware and virtualization technologies to form a shared infrastructure that enables web-based value added services. The three predominant service models are infrastructure, platform, and software-asa-service. Infrastructure-as-a-Service (IaaS) can be defined as the use of servers, storage, and virtualization to enable utility like services for users. Security is a big concern within IaaS, especially considering that the rest of the cloud service models run on top of the infrastructure and related layers. Platform-as-a-Service (PaaS) providers offer access to APIs, programming languages and development middleware which allows subscribers to develop custom applications without installing or configuring the development environment. Software-as-a-Service (SaaS) gives subscribed or pay-peruse users access to software or services which reside in the cloud and not on the user's device. Understanding the cloud service models is critical in determining if cloud services or hosting are an appropriate business solution, and if so, which model best balances the level of control required versus reduced hardware, configuration, and maintenance costs. Cloud computing offers many benefits to organizations; it has enabled collaboration amongst disparate communities and workgroups, and has overcome challenges that have plagued existing business solutions. However, the security, privacy, and integrity of the cloud are of prime importance and there are many challenges that exist. At the present time there seems to be a lot of momentum behind the adoption of cloud computing despite these. This may simply be a trend, an indication that society truly wants their data to be available whenever from anywhere, or a sign that few understand the associated risks.