Is it true to say that both a "shared server environment " and a "VPS environment" can be either IaaS or PaaS?

Question

Say I rent a DigitalOcean 20$ "VPS environment" (IaaS) or a SiteGround 10$ "shared-hosting environment" (PaaS).

As far as I know, in both cases I share hardware with other customers (both constellations aren't "dedicated" - either dedicated "on-perm" or dedicated in any other hosting model).

From what I just described, I get the impression that the notion of a "shared hosting environment versus a VPS environment" is misleading because in both cases there is direct sharing of one system (one hardware system - "shared" or "VPS").

Hence I ask, is it true to say that both a "shared server environment " and a "VPS environment" can be either IaaS or PaaS?

Answer 1

A VPS service provides you with infrastructure in the form of private virtual machines. You have access to these VMs as if they were regular servers (e.g. via SSH). The infrastructure itself is the product. The VMs almost always run on shared hardware.

A "shared hosting" service provides you with an application environment. You may or may not have access to the underlying infrastructure; the infrastructure exists but the application platform is the product. The environment almost always runs on shared hardware.

You're correct that both VPS and "shared hosting" providers use shared resources for their service, but "shared hosting" providers only provide infrastructure insofar as it is required for the application to function.

For that reason "shared hosting" environments are usually categorized as PaaS. VPS services are IaaS, but many providers also offer PaaS products.

Answer 2

Usually, Only a VPS hosting can be either.

While an IaaS is always VPS, what's commonly called "shared hosting plan" is PaaS in which a client shares the same hardware and webserver software with different customers (due to sharing a webserver, it's not a VPS --- Virtual Private Server).

In a PaaS (of the subtype Pass;VPS) only the hardware is shared (so it's indeed a "shared server", but only in that sense).