15 February 2022
Demystifying Cloud Computing – Part 1: IaaS, PaaS, SaaS
by Stephanie Schuldes
“The cloud“ is a collective term for various services and delivery models. This article is the first of a two-part series where we take you through the basics. Part one focuses on the service models IaaS, PaaS and SaaS. The next article will look at the deployment models Public, Private and Hybrid Cloud.
Cloud computing is an umbrella term for the delivery of computing capabilities and resources over a network, most commonly the internet. According to the NIST, cloud computing is defined by five core characteristics:
To enable a system to meet these five requirements, the task of managing infrastructure is transferred from the user to the cloud provider. There are several ways in which the responsibility for the hardware and software stack can be divided between these two parties. As a result, three cloud service models have emerged: IaaS, PaaS, and SaaS.
With IaaS, the technical infrastructure is provided by a data center (hardware, network, storage, servers). Instead of purchasing their own servers, users can rent them on an as-needed basis. The IaaS provider is responsible for maintenance. From the operating system on up, the user is in charge of everything else. In essence, users have a virtual data center.
Examples of IaaS
PaaS provides an integrated runtime and development environment (including hardware, software, and maintenance) as a service via the data center. Thus, the user pays for the use of databases, file systems, or application servers, for example. The user manages his or her own applications and data.
Examples of PaaS
With SaaS, complex software is made available via the data center. Instead of a one-time license purchase and local installation, the software is provided as a service (similar to buying vs. renting a car). This trend has been aided most by web services, which are typically billed on a per-call basis.
Examples of SaaS
Every organization must decide which methods are best to use in the development process. Projects with limited resources and a focus on simple applications, processes, or platforms can save a lot of time and money by developing exclusively in the cloud. For most applications, organizations that value flexibility, performance, security, and portability benefit from the hybrid combination of cloud and existing on-premises infrastructures.
IaaS, PaaS, and SaaS all provide distinct advantages to businesses in terms of scale, performance, and cost savings. IaaS, for example, is ideal for organizations looking for quick deployment cycles from a scalable system. PaaS retains infrastructure control while removing much of the back-end work typically associated with developing and maintaining applications. Finally, SaaS enables businesses to quickly and easily access new applications, as well as regular access to new features and upgrades.