What Is Cloud Computing? A Beginner’s Guide to SaaS, PaaS, and IaaS

Episode 1

The HULK virtualization team launches a series to explain the history and concepts of cloud computing in plain language, and later will share practical experiences with OpenStack, Docker, and other technologies.

According to Wikipedia, cloud computing is an Internet‑based model that provides shared processing resources and data on demand, allowing rapid provisioning and release of configurable resources such as networks, servers, storage, applications, and services.

In simple terms, a small company can avoid buying and maintaining physical servers by purchasing on‑demand compute resources from a cloud provider; resources can be scaled up or released as needed.

Wikipedia lists three main service models:

Software as a Service (SaaS) : consumers use applications run on the provider’s cloud infrastructure.

Platform as a Service (PaaS) : consumers deploy their own applications using the provider’s runtime environment, libraries, and tools.

Infrastructure as a Service (IaaS) : consumers provision fundamental computing resources (CPU, storage, networking) and run arbitrary software, including operating systems and applications.

The author argues that IaaS is currently the most popular model because it offers a natural transition from traditional IT: simply provide a "server" to users.

The team focuses on IaaS solutions for internal use, citing three main reasons for not buying public cloud services: high cost at large scale, limited flexibility of public offerings, and security concerns of keeping servers under their own control.

Their IaaS stack relies on open‑source software—Linux, OpenStack, KVM, QEMU, and Open vSwitch—because commercial solutions like VMware are too expensive and cloud providers do not share their proprietary implementations.

Reference: https://en.wikipedia.org/wiki/Cloud_computing

To be continued...