IaaS (Infrastructure-as-a-Service) and PaaS (Platform-as-a-Service) are well known service models in the wold of cloud computing. They are used for hosting applications in the Cloud.
But they have a major difference, that we will cover below.
The main difference
The explanation is simple. IaaS and Paas have different approaches of hosting the application in the web:
- IaaS model provides the infrastructure that consists of computers, data storages, networks, operating systems, etc. Clients deploy applicatoins to this environment and manipulate it as they want (they can install all needed software, set up load balancing and networking). When the infrastructure is becoming to deal badly with new big amount of load/traffic, clients increase scalability by buying more machines for existent infrasructure.
- PaaS works in the next way: client easilly deploys the app to PaaS provider and app starts working in the cloud. But the details of load-balancing and networking are hidden form client. In many cases the applicatons should be previously configured to be suitable for selected PaaS-provider. Anyway, it helps a lot to concentrate on product development, and not on deployment.
If you want to know more, I have another article, that covers IaaS, PaaS and SaaS a little bit deeper.