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IaaS, PaaS, SaaS and hosted appliances: Making sense of the cloud and what it offers

(Image credit: Image Credit: Wright Studio / Shutterstock)

“Moving to the cloud” has become one of the most popular phrases in IT and management in recent years. By 2020, LogicMonitor predicts that 83 per cent of enterprise workloads will be cloud-based. Companies are migrating to the cloud for a number of reasons – from setting up full environments in order to eliminate in-house IT, to taking advantage of virtual environments to utilising a growing host of SaaS solutions for just about anything.

Cloud has indeed become ubiquitous, with vendors of all sorts offering cloud solutions to a growing number of interested customers. However, oftentimes, it's not a “cloud” solution companies need, but rather a SaaS solution – and the two are definitely not the same. Cloud refers more to the infrastructure of a service, including the servers, environment, operating systems, etc., while SaaS is fully-formed applications that companies can benefit from immediately.

Often, companies that sign up for “cloud” services are expecting SaaS solutions, but quickly discover they actually signed up for a do-it-yourself cloud solution thus leading to disappointment, tensions and complaints. It makes sense, then, for companies to educate themselves on exactly what the differences are between “cloud” and SaaS. What will they get with the former and the latter? When is one or the other appropriate? What questions should they ask service providers, and themselves?

Iaas, Paas and SaaS: The question of what you get when you “move to the cloud” has actually been a source of confusion for many, and as a result, the cloud industry has redefined itself in order to ensure that everyone is on the same page. “Cloud” today comes in three different flavors: Infrastructure as a Service (IaaS), Platform as a Service (PaaS), and Software as a Service (SaaS).

IaaS: Infrastructure as a service is essentially what people mean when they say they are moving to the cloud in order to reduce or eliminate their on-premises IT systems. This is the infrastructure component of the cloud, an infrastructure that offers storage, memory, elasticity to increase or reduce capacity, etc. Companies would use it just as they would a local IT infrastructure, running their applications and services on the now-remote system. Examples of IaaS systems include AWS EC2, Rackspace, Google Compute Engine (GCE) – the “hardware” systems that provide full infrastructure services, for which companies pay by the byte.

What they're all about

PaaS: Once you're “in the cloud” - i.e., you have moved your resources to an IaaS system – your IT teams will want to get to work. For that, you need computing resources, such as access to languages, virtualised environments, etc. That's what PaaS is all about: Platforms feature computing resources that led developers to build applications and services, and include tools to ensure that they are operating properly and can be used at scale, such as auto-scaling, load balancing, capacity provisioning, etc. If IaaS provides the structure for developers to do their work in the cloud, PaaS provides the resources to do so.

SaaS: For many, this is what they mean when they think “cloud.” SaaS includes the many applications that we have come to identify with the cloud, including Google Apps, Office 365, Salesforce, Dropbox, Slack, Hubspot, etc. All these are examples of full applications that users can take advantage of, using them as they would any on-premises software application.

All three are important to the way organisations work with the cloud, but the latter has engendered some confusion among cloud users. There are SaaS applications native to the cloud, and then there are solutions that migrated to the cloud but are based on on-prem technologies.

The difference, one could say, is that true SaaS is “of the cloud,” offering the full advantages of cloud deployment, while migrated services are just “in the cloud” - basically the same as they were, but in a different location.

Email provides a good example of that difference. On-premises email systems that are deployed to the cloud – where a company buys a domain and runs its own cloud-based email server – have the same capabilities and limitations as local email deployments. To expand capacity on-premises, you have to buy a bigger storage system, and to expand a cloud-based email deployment, you have to rent more space. In a native email system like Gmail, though, you don't have to do anything to get more capacity (except pay for more space on the server).

Making things easy

The advantages of a true cloud solution vs a migrated on-prem one go beyond overcoming space limitations. Gmail and other cloud-based services (Office 365, Salesforce, etc.) will also provide elasticity, scalability, virtual machines, backhauling, auto-updating, and other aspects of computing that one would have to deploy, buy, install, or otherwise acquire an on-premises solution – or as part of what some call a “fake cloud” solution, where systems are deployed in the cloud but do not provide the advantages of true cloud solutions.

The same goes for cybersecurity companies – especially legacy companies that are building out their cloud services based on what they offered for the on-prem era - that market themselves as SaaS. However, not all are true SaaS; instead, what they offer more resembles a hosted appliance than SaaS.

The term “hosted appliance” refers to a preconfigured in-house solution that an organisation deploys that lets them host their own virtual cloud solutions. It's as if they are hosting a cloud of their own in their offices. One of the big advantages of doing this is to ensure security; credentials do not have to be sent online reducing the risk that they can be stolen by bad actors.

But in this situation users lose out on the advantages of true SaaS – redundancy (e.g. across locations), peak management, scalability, outage management, etc. If you have a problem with a service on a hosted appliance - or on a “fake cloud” - you’re basically on your own. If something goes wrong with SaaS, the service itself will ensure that things get back on track, as per their contract with the customer.

“The Cloud” is supposed to make things easy for companies, and in most ways, it does. But, only if it’s truly “of the cloud,” with all the attendant conveniences you get with true SaaS. As we’ve seen, there are solutions that are on the cloud, but not of the cloud, and those aren’t necessarily any different than what you get with an on-prem. Like with any new innovation, you need to make sure you are getting what you really need and understand what's being offered – and to make the appropriate decision that will best suit their needs.

Yoram Salinger, CEO, Perception Point (opens in new tab)

Yoram Salinger is the CEO of Perception Point, leading the company’s growth, strategy and management. Previously, he was CEO of Redbend and Netgame, and COO of Algorithm Research.