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What Is "the Cloud"? Cloud Computing for Beginners

The cloud is other people's computers, rented by the minute. What cloud computing actually is, the difference between IaaS, PaaS, and SaaS, what AWS, Google Cloud, and Azure sell, how cloud billing works, and how much of it a first app really needs.

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"It's in the cloud" sounds like the data is floating somewhere. It isn't. It's on a computer in a building, owned by a company that rents it to you. That's the whole idea — but the details decide how much you pay and how much work you do.

The short version

Cloud computing means renting computing resources — servers, storage, databases, networking — from a provider, over the internet, and paying for what you use.

Before the cloud, running an app meant buying servers, putting them in a data centre, and maintaining them for years. With the cloud, you click a button (or run a command) and have a server in a minute. When you don't need it, you delete it and stop paying.

Three layers: IaaS, PaaS, SaaS

Cloud services are often grouped by how much the provider does for you.

Infrastructure as a Service (IaaS) — raw building blocks: virtual servers, disks, networks. You install and manage everything on top. Examples: AWS EC2, Google Compute Engine, Azure Virtual Machines, DigitalOcean Droplets, Hetzner Cloud.

Platform as a Service (PaaS) — you give it your code; it handles the servers, operating system, scaling, and often the database. Examples: Heroku, Render, Railway, Fly.io, Google App Engine.

Software as a Service (SaaS) — finished software you use through the browser. Gmail, Slack, Notion, Stripe. You don't run anything.

A handy analogy: IaaS is renting an empty kitchen, PaaS is a kitchen with a chef who cooks your recipe, SaaS is ordering from a restaurant.

The big three, and everyone else

Amazon Web Services (AWS), Microsoft Azure, and Google Cloud are the largest providers. Each sells hundreds of services — not just servers but databases, file storage, machine learning, email, queues, and more.

They're powerful and they're complicated. Setting up a simple app on AWS involves choosing among many services, configuring permissions, networks, and security groups, and reading a bill with dozens of line items.

Smaller providers (DigitalOcean, Hetzner, Vultr, Linode/Akamai) offer simpler, cheaper servers. Platforms built on top of the cloud (the PaaS list above, and developer tools like EasySpawn) hide the complexity entirely.

How cloud billing works

Cloud pricing is usage-based. You typically pay for:

  • Compute — per hour or per second a server runs, depending on its size.
  • Storage — per gigabyte per month.
  • Data transfer — per gigabyte sent out to the internet ("egress").
  • Managed services — databases, load balancers, and so on, each with its own meter.

That's great for flexibility and dangerous for surprises. A server you forgot to delete, a database left at a large size, or unexpected traffic can all produce a bill you didn't plan for. Set a budget alert on day one. (How Much Does It Cost to Run an App?.)

Why people use it

  • No upfront cost. No hardware to buy.
  • Fast. New servers in minutes, not weeks.
  • Scalable. Add capacity when traffic grows; remove it when it drops.
  • Global. Run your app in data centres near your users.
  • Managed services. Let the provider handle backups, patches, and failover for databases and more.

The downsides

  • Complexity. The big providers expose you to every decision.
  • Unpredictable bills. Usage-based pricing can surprise.
  • Lock-in. The more provider-specific services you use, the harder it is to move.
  • Still your responsibility. The provider secures the data centre; you secure what you put in it. Misconfigured storage buckets and open databases are a leading cause of data leaks.

What a first app actually needs

Much less than the cloud offers. A typical first app needs:

  1. Somewhere to run your code.
  2. A database.
  3. File storage for uploads, maybe.
  4. A domain and HTTPS.

A PaaS or managed platform gives you all four with a fraction of the setup, on a predictable monthly price. You can always move to raw cloud infrastructure later, if you ever need the control.

EasySpawn is a managed layer on top of cloud infrastructure: a persistent workspace per project with Claude Code, managed databases, SSL, and your own domain — on flat monthly pricing rather than a usage meter. See pricing or join the waitlist.

Related: What Is a Server? · What Is Serverless? · VPS vs PaaS

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