Infrastructure as a Service (IaaS) is the best fit for a business looking to offload hardware management but retain control over operating systems, applications, and possibly some networking components like firewalls and load balancers. IaaS provides virtualized computing resources over the internet, where the cloud provider manages the physical infrastructure, but the customer manages the virtual resources. This differs from Platform as a Service (PaaS), where the provider manages the runtime environment, and Software as a Service (SaaS), which does not provide control over operating systems or applications.