Cloud Computing, Explained Without the Jargon

I teach this topic every semester, and the same thing happens every time: students panic at the acronyms, then realise the underlying ideas are genuinely simple. Let me strip out the jargon.

The core idea

Cloud computing means renting computing resources instead of buying them.

That's it. Rather than purchasing a server, putting it in a room, cooling it, securing it, and replacing it every few years, you rent capacity from someone who already runs data centres at scale.

The three service models

The classic way to understand these is the pizza analogy.

IaaS — Infrastructure as a Service

You rent the raw hardware: virtual machines, storage, networking. You install and manage everything on top.

Like buying ingredients and cooking at home. Maximum control, maximum work.

Examples: AWS EC2, Google Compute Engine, Azure VMs

PaaS — Platform as a Service

You get a ready-made environment. You supply your code; the platform handles the operating system, patching, and scaling.

Like a meal kit. Ingredients prepped, you assemble.

Examples: Vercel, Heroku, Google App Engine

SaaS — Software as a Service

Finished software you simply use. No installation, no maintenance.

Like ordering delivery. You just eat.

Examples: Gmail, Google Docs, Dropbox, Canva

The three deployment models

Public cloud — shared infrastructure run by a provider. Cheapest, most scalable. Suitable for the overwhelming majority of businesses.

Private cloud — infrastructure dedicated to a single organisation. Chosen for strict regulatory or data-residency requirements. Banks and hospitals often need this.

Hybrid cloud — a combination. Sensitive data stays private; public cloud absorbs traffic spikes.

What actually matters in practice

For a typical small business or portfolio site, you'll be on public SaaS or PaaS and you'll never think about servers. That's the correct choice. Don't over-engineer.

The genuine trade-off to understand is this: cloud is cheaper to start and more expensive to scale badly. Costs escalate when nobody is monitoring usage. Set billing alerts on day one — this is the mistake I see most often.