December 2, 2019 By Tessa Rodes 6 min read

In this lightboarding video, I’ll explain the basics of Platform-as-a-Service (PaaS).

PaaS is a cloud-based computing model that allows development teams to build, test, deploy, manage, update, and scale applications faster and more cost-effectively.

I’ll show you how PaaS relates to Infrastructure-as-a-Service (IaaS) and Software-as-a-Service (SaaS) and lay out the pros and cons of using a PaaS solution.

If you like this video and want to see more like it, make sure you subscribe to the IBM Cloud YouTube channel!

Learn more

Video Transcript

Platform-as-a-Service (PaaS) Explained

Hi, I’m Tessa Rodes, and I’m a designer on IBM Cloud. And today, we’re going to talk about Platform-as-a-Service (PaaS)

It’s hard to define Platform-as-a-Service without talking about its neighbors: Infrastructure-as-a-Service (or IaaS) and Software-as-a-Service (or SaaS).

What is Infrastructure-as-a-Service (IaaS)?

So, let’s start with the foundation here, with IaaS. IaaS is a set of compute, networking, and storage resources that have been virtualized by a vendor so that a user can access and configure them any way they want.

In design, we have a concept of talking about users—called personas—and the persona for IaaS is a System Admin or an IT Admin.

What is Software-as-a-Service (SaaS)?

Let’s jump up to the top with Software-as-a-Service—that’s the easy one. Software-as-a-Service is just software that you don’t have to install on your machine and you don’t have to manually update. 

And so, the user for Software-as-a-Service could be anyone. In fact, if you’re watching this on YouTube right now then you’re a user of Software-as-a-Service. It’s usually charged on a subscription model rather than a one-time license fee.

What is Platform-as-a-Service (PaaS)?

And that brings us to Platform-as-a-Service. PaaS takes advantage of all the virtualized resources from IaaS and then just abstracts them away so the user doesn’t have to worry about managing any of those virtualized resources.

The user for PaaS is not a System Admin usually—it’s usually a Dev. In IBM we call this Dev “Jane,”—that’s the name of our persona. 

And so this whole metaphor—the pyramid metaphor—is meant to indicate that as you move down, you’re increasing complexity in terms of your knowledge and management of infrastructure resources, and you’re increasing the ease of use.

The car metaphor for IaaS, PaaS, and SaaS

Another metaphor I use when I’m talking to the designers on my team about PaaS is having to do with a car. 

So, in this metaphor, IaaS is like leasing a car.

So, if you’ve ever leased a car, you probably did a lot of research and you care about the specs of the car and the performance. You care about the color of the car, and what kind of car it is. You’re the one driving and you’re paying for it. You’re also paying for the gas and any tolls or maintenance.

With Platform-as-a-Service in this metaphor, that’s more like renting a car. So, say you’re on vacation and you just got out off at the airport, and you’re going to pick up your rental car—you don’t really care what color it is, you don’t even care about the specs of it, but you’re still driving and you’re paying for the gas and any tolls you go through.

Software-as-a-Service is again, the easiest one. That one’s more like getting a taxi or an Uber. So, with the taxi or Uber, you don’t care at all about what kind of car it is, what color it is, and in fact, you’re not even the one driving or paying for gas or any tolls because that’s baked into the price.

What does the vendor provide and what does the user provide?

So, let’s think about what that means in terms of cloud computing and what the vendor provides and what the developer, or “Jane”, provides.


So, the vendor provides servers, storage, networking, virtualization, middleware, the operating system, and the runtime. 

All that leaves for the developer to provide is their data and applications.

So, this is the developer and this is the vendor—the cloud vendor. 

Pros and cons of Platform-as-a-Service (PaaS)

So, there are some pros and cons with that just like with leasing, renting, or getting a taxi.

Pros of PaaS 

The pros for using Platform-as-a-Service are that it’s generally assumed that it’s quite fast and easy to get an app up and running, which is great. 

It’s easy to create and delete the resources, which is important for, say, you’re running a proof-of-concept app for a conference and you want to spin it up right before the conference and then delete it right after. You’re not paying for the whole month, and it’s easy to spin it up and delete it.

Also, that really results in some cost benefits. Another cost benefit of Platform-as-a-Service is that you don’t have to pay for a full-time system or IT admin to run this app, they can focus on something else. 

And another pro is that a lot of providers of Platform-as-a-Service have been building out some tools on their platform. So, you can use DevOps tools, collaboration tools, and there’s a lot of API marketplaces that have been coming out, which is great because you can just take those services and plug them into your app, again still without having to worry about any of this.

Cons of PaaS

There are some cons to using Platform-as-a-Service. 

This big one is lack of control—but some people will still say that that is a pro because although some people like to pull all the levers and push all the buttons having to do with fine-tuning their infrastructure, a lot of people don’t want to have to worry about that, nor do they have the understanding or ability to do that.

Another con is the vendor lock-in—it’s a little bit hard to migrate your app; unless you’re using an open-source framework like Cloud Foundry, it’s a little hard to migrate a Platform-as-a-Service app from one cloud to another. So, make sure you trust and like your cloud provider before you choose it.

And then finally the performance at scale can be an issue. Performance at scale—so say that Jane the developer had a Platform-as-a-Service proof-of-concept app from that conference, and then she released it to 10,000 people the next day. It definitely won’t have the same in and out performance as if it was running on a dedicated bare metal server, for example. So, that’s a consideration to have.

Was this article helpful?

More from Cloud

Enhance your data security posture with a no-code approach to application-level encryption

4 min read - Data is the lifeblood of every organization. As your organization’s data footprint expands across the clouds and between your own business lines to drive value, it is essential to secure data at all stages of the cloud adoption and throughout the data lifecycle. While there are different mechanisms available to encrypt data throughout its lifecycle (in transit, at rest and in use), application-level encryption (ALE) provides an additional layer of protection by encrypting data at its source. ALE can enhance…

Attention new clients: exciting financial incentives for VMware Cloud Foundation on IBM Cloud

4 min read - New client specials: Get up to 50% off when you commit to a 1- or 3-year term contract on new VCF-as-a-Service offerings, plus an additional value of up to USD 200K in credits through 30 June 2025 when you migrate your VMware workloads to IBM Cloud®.1 Low starting prices: On-demand VCF-as-a-Service deployments begin under USD 200 per month.2 The IBM Cloud benefit: See the potential for a 201%3 return on investment (ROI) over 3 years with reduced downtime, cost and…

The history of the central processing unit (CPU)

10 min read - The central processing unit (CPU) is the computer’s brain. It handles the assignment and processing of tasks, in addition to functions that make a computer run. There’s no way to overstate the importance of the CPU to computing. Virtually all computer systems contain, at the least, some type of basic CPU. Regardless of whether they’re used in personal computers (PCs), laptops, tablets, smartphones or even in supercomputers whose output is so strong it must be measured in floating-point operations per…

IBM Newsletters

Get our newsletters and topic updates that deliver the latest thought leadership and insights on emerging trends.
Subscribe now More newsletters