What do the acronyms SaaS, PaaS, IaaS,... stand for?

We most often hear about SaaS, but many other types of products with *aaS acronyms are proliferating on the web, but what does this really mean?

SaaS stands for "Software as a Service"

Where "as-a-Service" simply represents the payment model for a piece of software or a platform. By definition, a product is a purchase made once and kept as long as it works. On the other hand, a service is paid for according to the time used, or otherwise via a predefined plan if the recurrence of the service's use is high.

In digital products, buying a piece of software (even though it is a product) is becoming less and less common, and the "as a Service" purchase model (i.e. in the form of a subscription) has exploded over the past few years.

This change is notably explained by the growth of the cloud, whose payment is based on usage time. There are many different types of products under this "as a Service" banner, here are the main ones:

SaaS - Software as a Service

This category is undoubtedly the broadest since it represents all software (web and desktop) sold in the form of subscriptions, monthly or annual.

The two most well-known software suites that have moved from a classic model to a SaaS model are Adobe Cloud and Microsoft Office.

PaaS - Platform as a Service

PaaS is the term used to define a cloud hosting service through which a developer can deploy an application without worrying about the infrastructure used under the provided platform.

Here are a few examples of "Platform as a Service" providers: Heroku, CleverCloud, Vercel, Netlify...

IaaS - Infrastructure as a Service

Infrastructure as a Service providers are hosts that make physical or software infrastructures available (through virtualization) such as VPS, dedicated servers, bare-metal servers...

If you don't know what a VPS is, here's an article dedicated to this subject!

You can find this kind of service at: OVH, Ionos, AWS and many others.

DBaaS - DataBase as a Service

Like all other managed services, setting up a database in the cloud avoids having to manually manage version upgrades, backups, the underlying infrastructure, deployment, etc...

Most popular DBMSs have a DBaaS version at hosts like: OVH (MariaDB, MySQL, PostgreSQL or Redis), CleverCloud (PostgreSQL, MySQL, MongoDB, Redis), MongoDB Atlas, etc...

AIaaS - Artificial Intelligence as a Service

Artificial intelligence systems such as machine learning and deep learning applied to tasks like natural language recognition and visual recognition are now directly available as services.

Some providers offer this, notably: AWS and IBM

FaaS - Function as a Service

Commonly called "Serverless", FaaS is a hosting service that takes care of launching and calling each of your software's functions independently and in an optimized way.

The most popular serverless hosts are: AWS, Google Cloud, Microsoft Azure

And many others

There are many products that can be offered as subscriptions, and new categories are appearing regularly. If you want an almost exhaustive list of "as a service" terms, you'll find what you need on this dedicated Wikipedia page: https://en.wikipedia.org/wiki/As_a_service