IAAS (Infrastructure as a Service): IAAS (Infrastructure as a Service) is the base layer and typically provide access to networking, virtual machines, storage. The client has the highest level of flexibility and management over resources compared to PAAS and SAAS.
PAAS (Platform as a Service): PAAS(Platform as a Service) provides flexibility to users that they no need to manage the underlying infrastructure like operating system, runtime, software maintenance, patching etc.PAAS is suitable for developers because of provider will manage OS, servers, storage, Networking. So they can only concentrate on the development of the application.
SAAS (Software as a Service): SAAS(Software as a Service) is most popular and easy to use. Because service provider takes care of all the responsibilities like networking, storage, servers, firewalls, runtime, data, application. whenever client chooses cloud type as SAAS, he/she don’t have any control over the resources under the application and responsibilities.