Infrastructure as a Service (IaaS) provides virtualized computing resources over the internet. In an IaaS model, the cloud provider hosts the infrastructure components that are traditionally present in an on-premises data center, including servers, storage, and networking hardware, as well as the hypervisor or virtualization layer. The IaaS customer has control over operating systems, storage, and deployed applications and sometimes limited control of select networking components (e.g., host firewalls). Platform as a Service (PaaS) and Software as a Service (SaaS) offer less control over the environment; in PaaS, you manage the applications and data, while SaaS offers no control over the infrastructure or the platform.