Deciding to take your business to the cloud requires a lot of planning and understanding. One of the biggest decisions is deciding between Infrastructure as a Service (IaaS) or Platform as a Service (PaaS). While IaaS and PaaS are similar in many ways, there are a few key differences between the two cloud computing models. Here we'll provide some guidance on finding the best cloud solution. (For some background on cloud computing, check out Cloud Computing: Why the Buzz?)

What Is IaaS?

Infrastructure as a Service refers to a model in which the hardware of a business - the server, storage and network core - is delivered as a service for a metered cost, acting like a utility. The company provides the services on demand, and it is up to the client to configure the operating system, the software and the database.

IaaS is the core package of cloud computing. If you want to fully integrate your business into the cloud, you will be outsourcing your hardware. The main attraction to IaaS is the ability to scale up or down depending on user demand. It also reduces capital expenditure for the hardware and the utility costs that come with buying and hosting hardware on-site.

What Is PaaS?

Where IaaS provides outsourced hardware to host an environment, PaaS provides a platform to develop applications that can be delivered over the Web. PaaS makes it possible for multiple developers to work on source code simultaneously.

In this environment, developers can test, develop, deploy and host applications via an online service. This online service allows developers to focus more on developing applications than on maintaining the hardware that would usually support them. Both IaaS and PaaS reduce capital expenditure, which allows an IT environment to focus more on strategy than hardware maintenance.

Where Things Get Complicated

While it may seem like IaaS and PaaS are significantly different, the two models have become increasingly similar. This has occurred as a result of the integration of tools now being packaged with IaaS offerings. These tools allow for the deployment of various clouds in one environment.
So, in theory, you could create a cloud that acted much like a PaaS offering. You could test, deploy, develop, host and maintain applications within this one cloud while still maintaining the computing, storage and network requirements of your IT environment in another.

This has led to speculation that eventually IaaS and PaaS will blend into one model. However, using an IaaS approach to develop a PaaS offering takes far more time than using a preexisting PaaS offering.

When You Should Use IaaS

IaaS has many benefits, but moving to a different infrastructure model can be difficult. IaaS is ideal for companies that have the need to scale resources quickly and regularly. It also able to accommodate heavier workloads almost instantly, or scale back during the lighter months.

New companies that may not have much capital can also benefit from IaaS. Without having to buy hardware, it is easy to save on operating and maintenance costs. This, in turn, allows companies to focus more on strategy than infrastructure maintenance.

Essentially, IaaS is an ideal solution for any company looking for an efficient way to scale infrastructure needs according to user demand. Instead of operating with too much or too little, IaaS makes it easy to compensate for fluctuations. However, these benefits can be offset if a company hosts massive troves of private data that can't be stored out of house.

When You Should Use PaaS

PaaS excels when multiple developers are working on a single application. It allows for the simultaneous use of a single source code and the ability to automate testing and deployment.

Something to keep in mind with PaaS is vendor lock-in. Unlike IaaS, PaaS often requires the use of a specific, proprietary language. This can cause an issue if a company wants to migrate to a different PaaS provider. With this in mind, it's best to research PaaS providers thoroughly before developing applications.

Choosing the Easiest Path

With both IaaS and PaaS offerings there is much to gain and much to think about in terms of which one will suit a particular company. While IaaS focuses more on storage, networking and computing, IaaS providers are starting to offer tools that allow for the deployment of multiple clouds, encroaching on what was once strictly PaaS territory. While these tools allow for the development of PaaS-specific clouds, the learning curve is much higher than with a regular PaaS provider.