SaaS, IaaS and PaaS: 3 Cloud Computing Service Models
SaaS, PaaS and IaaS are all models of cloud computing. Or to put it another way, pay-per-use and always available (24/7) cloud services.
Some of the factors that are leading companies to move to the cloud are: flexibility, scalability, ease of configuration, security, easy of payment or the savings that involve not having to make large investments in infrastructure to name a few.
But, What is the difference bewteen these three models?
Software as a Service
In the Software-as-a-Service (SaaS) model, access to certain software is provided. Users do not need to install or download anything on their endpoint devices. No matter the user´s location, the only two things a user needs are an Internet connection and a web browser. All development, management, maintenance, installations, updates, and backups are responsibility of the provider.
A great example of SaaS is RITech Personal Webmail, a new cloud service that leverages the patented technology RITech to protect organizations when their employees access their personal web mail from the corporate network.
Platform as a service
In the case of Platform-as-a-Service (PaaS) what is provided is the infrastructure, that is, access to a cloud-based environment in which users can create, develop, manage, test, host and distribute users´ applications. In this case, the user only has to worry about the software. The provider is responsible for installing (or implementing), managing and maintaining all the infrastructure: add resources if needed (scalability), security, the Operating System…
For example, Google App Engine is a PaaS solution
Infraestructure as a service
Finally, in the case of Infrastructure-as-a-Service (IaaS): only the infrastructure is provided (virtualized hardware necessary to build its own infrastructure: servers, storage, network connections, IPs, load balancers.) All these resources are distributed among the so-called Data Centers). In this case, the user is responsible for maintaining and managing the infrastructure: add more resources if necessary and prepare everything related to environment of the machines.
Two common examples of IaaS are AWS and Azure