Cloud Computing Basics – Understanding IaaS, PaaS, and SaaS

Posted by Vinay Vernekar 3rd January 2026

Look, if you’re trying to master cloud computing basics, don’t let the technical jargon scare you off. In my experience, the easiest way to think about the cloud is just using someone else’s computer over the internet so you don’t have to buy or manage the physical hardware yourself. It’s that simple.

Getting Down to Cloud Computing Basics

I remember the first project where we moved off-premise. We were tired of waiting six weeks for the procurement team to rack a new server. With the cloud, we did it in five minutes. That speed is exactly why companies are obsessed with it. You get servers, storage, and databases on demand, and you only pay for what you actually use.

When we talk about cloud computing basics, we’re really talking about five main things that make a service “cloudy.” First, it’s self-service. You don’t need to call a guy named Bob in the server room to get more space. Second, you can get to it from anywhere. Third, the provider pools resources for lots of customers. Fourth, it scales fast. And finally, it’s a measured service – like your water bill.

The Three Service Models You’ll Actually Use

This is where things usually get a bit blurry for folks. I’ve seen plenty of developers get these mixed up in interviews. Here is the short answer: it’s all about how much of the work you want to do yourself. Let’s break it down.

  • IaaS (Infrastructure as a Service): This is the raw stuff. You’re renting the virtual hardware. If you want to know more about the nitty-gritty, check out this guide on what IaaS actually is.
  • PaaS (Platform as a Service): This is for the builders. You don’t care about the OS or the hardware; you just want to push your code and have it run. It’s a huge time-saver. You can read more about how PaaS works here.
  • SaaS (Software as a Service): This is what most of us use every day. Think Salesforce or Gmail. You just log in and use the app. If you’re curious about the business side, here’s a deep dive into SaaS explained.
A professional 3D isometric diagram showing the layers of cloud computing: physical server infrastructure, developer platforms, and end-user software applications.
A professional 3D isometric diagram showing the layers of cloud computing: physical server infrastructure, developer platforms, and end-user software applications.

Deployment Models: Where Does the Data Live?

So where does this stuff actually sit? Most of the time, you’ll be on a Public Cloud like AWS or Azure. It’s cheap and it works. But I’ve worked with banks that wouldn’t touch a public cloud with a ten-foot pole, so they build a Private Cloud in their own data center.

Now, most big companies end up with a Hybrid Cloud. They keep the super sensitive stuff on their own servers and put the web apps on the public cloud. It sounds great on paper, but honestly, it can be a real headache to manage if the integration isn’t solid. And then there is Multi-cloud, which is just using different providers so you aren’t stuck with just one.

Security in Cloud Computing Basics

Here’s the thing: most people think the cloud provider handles all the security. That is a huge mistake. It’s a shared responsibility. The provider secures the physical building and the hypervisor, but you are still responsible for your data and who has access to it.

I’ve seen teams get into real trouble because they left an S3 bucket open to the public or didn’t set up proper Identity and Access Management (IAM). So, you’ve got to think about encryption and logging from day one. It isn’t just an “IT thing” anymore; it’s everyone’s job.

Pro tip: When you’re in an interview, don’t just recite definitions. Talk about a time the cloud helped you solve a real business problem, like scaling a database during a holiday sale. That’s what actually gets you hired.

Look at this quick example of how easy it is to start a server using a command line. You don’t need to be a hardware expert to do this anymore:

aws ec2 run-instances - image-id ami-0123456789abcdef0 - count 1 - instance-type t3.micro

One command and you have a server running. That’s the power we’re talking about here. But remember, once it’s running, you’re paying for it. So don’t forget to turn it off when you’re done!

Key Takeaways

  • Cloud computing basics are all about on-demand access to tech resources.
  • You can choose between IaaS, PaaS, or SaaS depending on how much control you need.
  • Public cloud is common, but hybrid is what most big companies actually use.
  • Security is a shared responsibility – don’t assume the provider does everything.
  • The main goal is speed, flexibility, and saving money on hardware.

Mastering cloud computing basics isn’t just about passing a cert or knowing the buzzwords. It’s about understanding how to use these tools to build things faster and cheaper than we ever could ten years ago. So, the next time someone asks you what the cloud is, just tell them: it’s the end of waiting for hardware.

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