Do you remember Open System Interconnection (OSI) model? Is that true we ascend high and higher with empowerment from cloud computing?

Infrastructure as a service (IaaS), platform as a service (PaaS), and software as a service (SaaS) are three main cloud computing options. Each comes with a tradeoff of control vs. convenience. It is well explained in this RedHat article with a picture below:

In my personal view, even there is not a 100% one to one match with cloud computing and OSI, they do overlap for the most part. Therefore, cloud options are inserted in the correct approximate place in my graph. Organizations should consider software as a service (SaaS) as the first choice for the obvious reasons: it removes the concerns of entire stack management and also development, testing, and all around effort.

Cloud first, then SaaS first.