What are the IaaS, PaaS and SaaS service models? What are they used for and what is the difference between them? This article will help you find the answers to these questions.
What is the cloud?
Cloud computing is a way of providing remote access to computing resources through the internet. The cloud is built using multiple physical servers that work in a single system. These servers are segmented into virtual machines (VMs). Just like a physical server, a VM has a CPU, RAM, storage etc. However, the configuration of each VM is not limited by the physical hardware on one machine. For example, you can increase the amount of RAM or turn off CPU cores at any given moment. This is possible because virtual machines use the resources of multiple physical servers at the same time.
Clouds are used for a variety of corporate tasks, such as deploying e-commerce projects, data bases, ERPs, mail servers etc. In other words, the cloud is a virtual IT infrastructure which can be used to deploy any corporate systems and applications.
Why do companies choose cloud solutions? Here’s a couple of reasons:
- access through the internet, no matter the time or the user’s location;
- no need to hire administrators, update software or hardware – this is the provider’s responsibility;
- instant scaling through upgrading virtual resources;
- various access rights levels for users;
- comprehensive services and support.
IaaS, PaaS, SaaS and XaaS are cloud service models; the difference between them lies in the levels of the tasks they solve. The IaaS model provides the client with the computing resources of the cloud; this infrastructure is used to deploy software solutions. PaaS is a model which includes cloud resources and pre-installed tools for various tasks. SaaS users get a full solution, which only needs to be applied; it’s likely that you’ve encountered SaaS services in your everyday life. All of these models can be broadly defined as XaaS, meaning «Anything-as-a-Service».