IaaS, PaaS, or SaaS are cloud service delivery models. The way they relate to each other is often depicted as a pyramid with different levels of information control. The top is the end user who works with personal data, "wrapped" in a program or service with a user-friendly interface. The program or service is deployed on some technological platform, this is the second level of the pyramid. Finally, its basis is the infrastructure: virtual servers, computing power, drives and communication channels.

SaaS (Software-as-a-Service). This cloud model is the most common. Programs and services are developed and maintained by the provider company, it places them in the cloud and offers them to the end user through a browser or an application on its PC. The client only pays the subscription fee (or uses the service for free), the provider handles the updating and technical support of the programs. SaaS services can provide a place to store files (Dropbox), an office suite of documents for work (Google Doc, Microsoft Office 365), help organize photos (Flickr), or communicate with other people (Facebook). An ordinary user is the main client of the SaaS services.

PaaS (Platform-as-a-Service). In this case, the cloud provider provides access to operating systems, development and testing tools, database management systems. The provider controls not only servers, data storage systems and computing power, but also offers the user a choice of certain platforms and means of managing them. The examples of PaaS are the following: Google App Engine, IBM Bluemix, Microsoft Azure, VMWare Cloud Foundry. Software developers are the users of PaaS services.

IaaS (Infrastructure-as-a-Service). Under this model, the customer receives information technology resources – virtual servers with a certain computing power and memory volumes. All the hardware is handled by the provider. It installs software on them to create virtual machines, but does not install and maintain user software. The provider controls only the physical and virtual infrastructure. The examples of IaaS are the following: IBM Softlayer, Hetzner Cloud, Microsoft Azure, Amazon EC2, GigaCloud. IaaS customers are system administrators of companies.

From the point of view of the end user, SaaS is the most understandable and convenient cloud model. It is often easier and more efficient to use a ready-made SaaS service that already meets certain requirements. But ready-made solutions do not always exist, and in this case PaaS and IaaS models are impossible to replace.

As a cloud provider, we provide IaaS and PaaS cloud model. IaaS is an E-Cloud designed for corporate customers and built on the basis of the VMware platform. We provide the client with IT resources, with the help of which he builds his own infrastructure. You can learn more about the service and order a free trial access. E-Cloud service‎.

PaaS is the S-Cloud 2.0, a public cloud for applications and test environments built on the OpenStack platform and the KVM hypervisor. The client rents the infrastructure, independently manages the amount of resources and configures virtual machines using an API and a self-service portal. Learn more about S-Cloud 2.0 and order a free trial to see how it works. S-Cloud 2.0 service.

There is an interesting video about the cloud on our channel: