In an IaaS solution, the CSP provides access to the necessary servers, networks, virtualisation, operating systems, data storage and data management. When paying for access to cloud-based infrastructure, customers enjoy increased flexibility and more comprehensive cloud solutions. However, the customers are responsible for managing applications, data, runtime and middleware, and for taking care of any necessary updates and responding to unexpected software issues.
IaaS is essentially a self-service model; users can defer the expenses of purchasing and maintaining hardware, while providing their own software to run on it.