Difference between SaaS, PaaS, and IaaS and How to Distinguish.

When the Internet was in its nascent stage and still developing into something with a semblance to what we know it as today, electronic mail or email was the only, or at least primary, service that was provided. People had probably not even considered the possibility of it being a repository of information or a platform for other services. We have come a long way from those days of nascence. Today, we can accomplish almost anything over the Internet. We can learn, play, read, write, shop, sell, entertain and enjoy, all through the Internet. But note that we said almost anything. Which means, not everything. Even as the world advances, needs grow, facilities increase and the Internet is expected to make equal leaps to stay up-to-date. Developers and coders are working hard every day to bring more and more services in the world under the fold of the Internet. Virtualization is the order of the day. In this fast-moving world, we want everything to be given to us before we ask. We simply want to log in to the Internet and have whatever we need, ready to be used right from that moment.


It is from this demand for ready-made Internet solutions that SaaS, PaaS and IaaS arose. They stand for Software-as-a-Service, Platform-as-a-Service and Infrastructure-as-a-Service. They are mostly used by businesses, although there is quite a large market of these among individuals too. The basic idea behind SaaS, PaaS and IaaS is that businesses or individuals looking to build up their Internet services and resources will not have to do so from up. According to their needs, a part or all of the required Internet facilities would be availed from third-party vendors over the Internet itself. This highly eliminates the time, effort, resource and cost that would have been expended in setting everything up from scratch. Therein lies the appeal of SaaS, PaaS and IaaS.


Of course, each of these is different from each other in terms of how much is provided by the vendor and how much control is retained in your hands. But the common theme that binds them is that at least a fraction of the Internet services would be provided by a company whose job is to provide these services to other businesses. The equipment and resources used to provide these services are not kept on the premise of the business availing the service but is maintained by the vendor at their own location. Thus the business does not have to take responsibility for their upkeep and maintenance, but only pay a proportional fee to the vendor to do so for it. This definitely reduces cost in the long run and defers the liability of breakdown and security to the vendor.

Let us now look at what is exactly meant by SaaS, PaaS and IaaS. We will define and then lay out the advantages, disadvantages and applications of each first, followed by a comprehensive comparison of the three in one place for better understanding. Finally, we will talk about the scope of -aaS facilities and what the future holds for them.


SaaS – Software-as-a-Service

As of today, SaaS is the as-a-Service facility that provides the greatest portion of services among the most commonly used ones. From the name itself, it can be deduced that in SaaS, software is provided to the business via the Internet. The software does not reside on a server on the premise of the company. It is hosted by the vendor and provided in a cloud-based format to the buyer through a paid subscription, based on their needs.

Thus, the vendor literally manages each and every part of the IT needs of the buyer, from hardware maintenance to software upkeep. The buyer does not even need to download or install anything to their terminals – they just need to connect to the Internet, log in to the service via their account and voila! They can start working instantly on it. You might, however, need to install some plugins and use the API to access some functionalities that require direct hardware support. All your data is also stored in the servers of the vendor, so you can access your work from any device in any corner of the world as long as there is an Internet service there. On top of that, since everything is managed by the vendor, you only need to concentrate on the work you need to accomplish on the software and not on IT support. In a way, this saves precious time, money and effort, since you also do not have to invest in an IT team or worry about downtime.

Of course this also somewhat takes away the control that the client can exercise over his IT resources. He has to depend entirely on his vendor for every issue. If the vendor is unable to ensure the smooth running and security of his systems, it ends up affecting all the sensitive data and information of the company and all its customers. Also, SaaS might be scalable, but the subscription structure of the payment system prevents the client from being able to choose what he may or may not want. He may not get one service that is not included in the package or may have to pay for something he does not need.

Also, the fact that everything exists on a remote server implies that there is going to be heavy traffic of data. This has quite a few implications. First, the company has to ensure the highest possible speed of their Internet connection. Second, the constant data traffic may make sensitive data vulnerable to hackers and open up an easy avenue for the entry of malware into the systems. Last but not the least, portability becomes difficult and highly costly. If the client wishes to transfer to a different vendor, for whatever reason he or she may have, a lot of data has to be transferred. Automatically, the vendor will charge a hefty amount to allow you to do that, which may not be feasible in many cases.



The advantages that a company derives from utilizing SaaS are:

  • There is zero hardware, set-up or installation expenses. A SaaS system provides everything on a virtual medium, which greatly cuts all those costs.
  • The vendor automatically makes the required upgrades and takes care of all maintenance needs. The client does not have to worry at all about any of this or face the hassle of hiring or keeping an IT team for help.
  • All resources are accessible from any location and device. Since everything is on the cloud, all one needs is a secure system and the account details to access the system.
  • There is no need to individually install anything on all the devices of every employee as everything is accessible right from the web browser. This eliminates the need for a large amount of memory and compatibility issues, allowing the people to access the system without worrying about memory or hardware or software version.
  • It is quite scalable and customizable depending on the size and growth of the business. Packages are available based on whether the business is small, medium or large.
  • Better utilization of time, money and effort occurs, that would have been spent on the installation, maintenance and regular upgrades in an on-premise arrangement.
  • There is no risk of loss of data due to problems in individual terminals as all the data is stored and backed up in the remote servers of the vendor. All a person has to do is find another terminal, log in to their account on that and they are good to go.
  • Since the entire system is on the cloud, it is quite easy to define and delineate user spaces according to the access and authority that is given to them. There is no fear of one user mistakenly getting into the data of another.



Despite the many advantages, there are some drawbacks in any SaaS system too. Some of these are:

  • The biggest disadvantage of getting a SaaS solution has to be the loss of control on your system. The independence to design and modify the different parts to suit your changing needs is all but lost.
  • From this itself, it follows that scalability will be in discrete steps instead of a smooth one. You will have to make do with the different plans the vendor provides, and have to do with some other make-shift solution, or without one, till then.
  • Since every single bit of data exists on the off-premise server provided by the vendor, strong Internet connectivity is essential to have access to your work at all times.
  • When upgrading to a SaaS system, you will have to make sure your existing systems are compatible with it. You may have to do your research regarding which SaaS solution is best able to integrate as much of your existing applications as possible since most vendors will provide little to no support in this respect. If you find no such option, you may have to write your own code to establish the interconnections.
  • With your entire system in the server of the vendor, portability is an expensive action. On top of that, the coding, protocols and APIs of the existing vendor and the one you are planning to shift to might be widely different. This may, in turn, call for an extensive reworking of all the in-house applications to make it compatible with the new environment.
  • The other major concern is security. With the responsibility for ensuring security entirely in the hands of the vendor, there is little you will be able to do in terms of data security and downtime on the end of the vendor. There will also be a frequent exchange of sensitive data between the servers and the local memory, and this will incur significant risks to the data itself.



The best scenarios where you can use SaaS are:

  • SaaS is useful when the company wants a quick, ready-to-use solution.
  • SaaS is great for small projects that require less integration and more communication, especially collaborations and temporary partnerships.
  • Less frequently used applications, especially that need a wide reach and access over multiple platforms are best obtained via a SaaS solution.
  • If your staff is spread throughout the world and requires a common platform to work through, SaaS is the best option.
  • Smaller companies with fewer resources and experience benefit greatly from SaaS.


Some of the commonest and most well-known examples of SaaS are Dropbox, Bigcommerce, Salesforce, Gmail, Office365, Cisco WebEx, etc.


PaaS – Platform-as-a-Service

PaaS, or platform-as-a-Service, can be considered as the middle ground between SaaS and IaaS. The name itself suggests that in this as-a-Service facility, the vendor will be providing only the platform for software development to the developer as part of the paid service. It is now on the developer to create the software applications he or she requires for the job, according to his or her own needs. The vendor will deliver a suitable framework to the developers via the Internet. This framework will have a variety of components and tools that the developer can use and integrate into the application they are creating. As a result, the developer does not have to waste precious time on writing every line of code even for the most basic features, and can concentrate their time and energy on optimizing and enriching the application he is writing.


In PaaS, while the creative control is bequeathed to the developers, the responsibility for resource management still lies with the vendor. All the hardware and software components necessary to get the work done, like the servers, storage space and networking channels, are provided and maintained by the third-party PaaS facility provider. Included within this package is the provision for necessary, timely upgrades, data security, storage space, infrastructure, hardware and software needs. Not only that, but the vendor also provides the middleware necessary to integrate and interconnect various parts of the software. That way, the only things the programmer will be responsible for will be choosing and arranging the different constituents that will go into making the software. They will custom-create the necessary applications and test them out before launching them. Every other task is taken care of by the PaaS provider, thus creating a sort of black box, the operations inside which does not need to bother the developer.


The best way to explain PaaS is by comparing it to a Build-a-Bear soft toy-making process. The shop provides the various components you need to make the bear, like the unstuffed animal, the stuffing, the scent, the sound, the clothes and accessories and the staff to do the back-end tasks. All you have to do is choose what you want in your stuffed toy and these will be put together in the correct manner and order with your help to create the custom soft toy for you. The toy here is the application you want to create and your actions like stepping on the pedals and the rituals form the part where you work on the platform to put together your application. Needless to say, the oy components are the software parts, the middleware, the servers, storage and other resources provided by the vendor, while the work of the staff can be compared to the upgradation, maintenance and security provided by the vendor.


PaaS has the maximum number of takers in the business world, perhaps because it is a perfect balance between how much control is held by the client and how much by the seller. It provides an optimum level of control to the developer to create solutions tailor-made for his requirements, letting the vendor handle the daily operations and eliminate the need for IT support there.



The pros of PaaS, that propel it to the top spot in terms of service popularity, are:

  • As we have already mentioned, PaaS delegates the right amount of control to both parties, letting the developer develop and the vendor maintain. This ensures maximum efficiency and productivity for the company.
  • PaaS also helps save a lot of time and money because you do not have to hire an on-site IT team to look after the infrastructure and resources.
  • PaaS allows multiple users to work on the same platform together and at the same time, allowing teamwork and multi-tasking. It is also advantageous if you are collaborating with people who live far away.
  • PaaS is more easily scalable than SaaS, as the developer can opt for tools and customizations suited to his or her specific needs.
  • Since the developer does not have to expend time on writing preliminary code for components provided via the platform, he can concentrate on the more important details and nuances of the application. This also means one does not need in-depth coding knowledge to build an application.
  • PaaS is also highly available since neither the vendor nor the client has to take care of the entire system, but only the parts they are responsible for.
  • PaaS is the more economical choice among the three when it comes to making custom apps. SaaS does not allow that independence and requires extensive coding and integration procedures to allow this, while in IaaS, the entire work has to be done by the developer himself or herself. PaaS allows easy development and integration of apps on the vendor-provided platform with suitable portability options too.
  • PaaS provides an easy solution to the developer to support his application throughout the entire cycle of creation, testing, deployment, management and upgradation.
  • PaaS also allows one to migrate easily to the hybrid cloud system.



Despite being the best option for most businesses, PaaS does have some cons too. Let us look at them:

  • The issue of dependence on the vendor remains as it was in SaaS. Some of the most essential aspects of development are still in the hands of a third party, which is never the most reliable option. Data security and management, downtime, tech support, upgrades and maintenance of infrastructure and resources rest with the seller. So if they fail to upkeep the machinery on their side, you will face system failure too.
  • Integration remains a large concern. Since the different parts of the system are spread out across sites or premises, extensive integration is necessary to include every component into this system. This may become a hassle in a lot of instances, especially if you are upgrading from an on-premise to a cloud system and have a lot of legacy systems that cannot be replaced properly by a cloud component.
  • While portability is easier in PaaS than in SaaS, it is still a hassle. Unless the vendor has convenient migration policies and uses standard systems, migration can still end up being difficult and costly.
  • Since PaaS provides the platform for solution development to the company, it automatically implies that you are bound by that platform to carry out their operations. You may not be able to work with all the languages, tools and frameworks of your choice if support is not provided by the platform chosen by you.



PaaS gives the best results when used in the following cases:

  • The best use of PaaS lies in the creation of custom applications to suit the needs of the company and its customers.
  • PaaS is the optimum system to use if you have multiple developers working on the same application.
  • PaaS allows you to make use of different services from different vendors without any hiccups.
  • It is a great option if you are looking to employ a cycle of rapid creation, testing and application to come up with the best solution for your problem.
  • Companies, especially startups, that prefer to invest in the creative field and let the operational side be handled by those who have experience in it prefer using PaaS.

Google App Engine, Magento Enterprise, Windows Azure Cloud Services, AWS Elastic Beanstalk and Redhat OpenShift.


IaaS – Infrastructure-as-a-Service

Infrastructure-as-a-Service, or IaaS in short, is, quite literally, the virtual analogue of a traditional data center. This implies that the vendor provides the IT infrastructure for a company to the people, but it is up to these people to create, install and maintain the software to run the system. In fact, the business has full control with regard to what they want to do with the infrastructure and how they want to use it. The only job of the vendor is to provide the cloud-based services and look after the maintenance and security of the servers, storage, operating systems and networking channels. All other operations must be handled by the company staff themselves via the API or dashboard provided.

In a way, IaaS is the best choice for established businesses looking to upgrade to the latest technology as well as for entrepreneurs who are experts in their fields, especially in IT solutions, but are facing a constraint in space. In the former case, a large business looking to shift to cloud technology will already have an expert IT team on board, which was needed to manage the on-premise IT infrastructure. So, they do not need any ready-made solution when they upgrade. They will only be looking for the cloud-based infrastructure to which they can transfer their systems. The same goes for a business that is on the cusp of a major expansion or upgradation. They might be wanting to go through a smooth transition instead of replacing every bit of hardware and software one by one and making severe losses due to extended downtime. For the same reason but in a different circumstance, a startup that includes personnel with advanced programming and computer engineering knowledge but is low on resources and investment would also go for IaaS. With the basic infrastructure provided to them via cloud-based IaaS service, they do not have to worry about buying the hardware, OS, servers, storage as well as physical space for all the things separately. They can simply avail of an IaaS service from a vendor that suits them the most and they are good to go.

Of course, it is pretty much taken for granted that although IaaS does not require you to build up your system bit by bit, hardware by software, you are still responsible for setting everything up and maintaining it. IaaS is a big no-no for those looking for a quick, ready-to-use solution that will be handed to them by the vendor and they can use right off the bat. IaaS is for those who want complete control over each and every component of their IT system, and want it built up, managed and updated exactly according to their vision. They want to retain full control over the system and not have to adjust and compromise according to what the vendor has added in a package. However, they do not want to spend wads of cash on a physical data center. On top of a massive initial investment behind that, there also has to be constant expenditure for maintenance, repairs, bug fixes and so on, that the core team of the venture might prefer not to be bothered with. So, to be able to concentrate all their time in building up a robust and efficient structure on which the company can flourish, the responsibility of the infrastructure is delegated to the IaaS provider.



The upside of using an IaaS system is given below:

  • IaaS is the most flexible among all the -as-a-Services mentioned here. You can add, eliminate, modify and replace any part of the system according to your needs. Both dynamicity and scalability are maximum in an IaaS-based business structure, so that, as your business grows or changes through the years, you can easily tinker with the system to align it with your business needs.
  • IaaS systems, due to their nature, warrants the use of a pay-as-you-go model for pricing. As you add individual components, hardware or software, to the infrastructure, you pay for the set-up, usage and maintenance of those only, to the vendor.
  • The client is able to exercise full control over each and every section of their IT system, even though the infrastructure is not on-premise. Due to the personal investment in the company, the client and the employees will always do their best for the operation, repair, improvement and security of their systems, unlike the vendors, who will only do it because it is their job.
  • Another advantage of retaining full control is that any requirement, problem or emergency that arises would be given a solution tailored to the specific needs of the company by those that know the operations of the business inside out. These solutions will obviously work much better than what the vendor can provide.
  • The automated deployment of storage, servers, networking, processing capacity and any other required hardware makes it easy to use, modify and scale up an IaaS system.
  • IaaS also allows multi-tenancy, whereby, more than one user can make use of the deployed components of the system.
  • It is also easier to mix and match components from different vendors to create a perfect system for your business.



The downsides of having an IaaS system are:

  • The most apparent con of having an IaaS system is the simultaneous requirement of your team to know how to operate every single part of the system. Your team itself will have to handle the entire system, manage its daily operations, take care of all corrective and reparative measures and deploy the necessary level of security. They have to be taught and trained constantly to keep them updated on the latest tools and technology. Thus, if any emergency occurs, there will be no insurance from the vendor’s end.
  • The multi-tenant architecture of an IaaS system automatically raises data risks. There are huge chances of overlap and inaccurate channels of accessing corresponding databases in this system.
  • There is, of course, always the risk of the infrastructure itself being under security threats or breakdowns due to some issue at the vendor’s end. This is, however, a risk no user, whether they subscribe to SaaS, PaaS or IaaS, will ever overcome. At least the risk is the lowest in the case of IaaS.
  • One also has to worry about connecting legacy systems to the IaaS cloud system. Since a large chunk of the system is in the hands of the client, like applications, OS, runtime, middleware, security and data, the client must ensure that these are compatible with the resources held by the vendor.



An IaaS system works best in the following cases:

  • Companies going through a phase of rapid growth or upheaval greatly benefit from the use of IaaS. They can scale up their infrastructure proportional to their business, and make changes according to their evolving needs without having to buy, throw away and make space for physical resources.
  • New ventures find it very advantageous to use IaaS as it lets you have full control over your infrastructure without having to expend a lot of money and time on buying and setting up the hardware and software.
  • Large businesses too recognize the application of IaaS. It helps them retain their control over the entire system without wasting time or money on unnecessary resources.
  • IaaS also offers a lot of independence and flexibility in choosing what you want. If you have a project that is still in the pupal stages and you need highly customizable infrastructure to be able to easily scale or modify it according to the needs of the project, IaaS will have your back.


Great examples of IaaS systems are Microsoft Azure Virtual Machines, Amazon Web Services (AWS), Google Compute Engine (GCE), Cisco Metacloud, Magento Enterprise and Rackspace.


SaaS vs PaaS vs IaaS

It will not be a correct comparison if we sit down to decide which is better than which. Each of SaaS, PaaS and IaaS has its list of pros and cons and each work best in the environment that suits them and the client. If you try to forcefully apply one where the conditions are more conducive for another, you are bound to hit severe roadblocks and face issues that would have been absolutely avoidable. Thus, rather than going into that debate, we will do a side-by-side comparison for all three so it becomes easier for you to deduce which one will fulfil your needs best.


Facility ProvidedSoftware as a ServicePlatform as a ServiceInfrastructure as a Service
Major UserbaseSystem administratorsApplication developersEnd users
User ManagesNilApplication, DataApplication, OS, Middleware, Data, Runtime
Vendor ManagesApplication, OS, Middleware, Data, Servers, Storage, Runtime, Virtualization, NetworkingOS, Middleware, Servers, Storage, Runtime, Virtualization, NetworkingNil
UtilityAs business management softwareAs an app-building platformAs a virtual data center
User ResponsibilityMinimumIntermediateMaximum
Ease of OperationMaximumIntermediateMinimum
Need for Computer KnowledgeMinimumIntermediateMaximum


While it is true that all three of the as-a-Services are useful in their own ways, it cannot be denied that PaaS is a system that still garners a greater number of users due to the healthy balance between what stays under the purview of the user and the reins to which parts of the system is in the hands of the vendor. PaaS provides an optimum level of control to both, thus dividing up the powers and responsibilities in a most favorable manner. Perhaps, it is for this reason that 32% of all -aaS users have gone for PaaS, while it is 24% for SaaS and 12% for IaaS. However, in terms of revenue spent on an -aaS, SaaS stands on top, followed by IaaS and then PaaS. This has much to do with the pricing mechanism of each method, which means that in spite of maximum usage, the minimum budget needed to be allotted for a PaaS system is a proof of its cost-effectiveness.


Concluding Statement

Most of you will already have heard of SaaS, PaaS and IaaS before, alluding to the growing market for cloud-based business IT solutions. But, as with any other thing in the world, the -aaS realm does not stop here. It has been predicted that at the current rate, very soon, Everything-as-a-Service will become the norm of the day. Alternatively known as Anything-as-a-Service and often denoted by either of EaaS, XaaS or AaaS, Everything-as-a-Service is the future of the -aaS trend. It simply means that a day will come when each and every need of human beings, from that of individuals to those of the multibillion corporations, will be available and deliverable over the Internet. Cloud storage will be the only way to store and exchange data as well as perform tasks on them with the help of a virtualized interface.


SaaS, PaaS and IaaS will obviously continue their upward journey, but other -aaS facilities will also join the list. Some of the names already brewing in the scene are Hardware-as-a-Service (HaaS), Desktop-as-a-Service (DaaS), Metal-as-a-Service (MaaS), Database-as-a-Service (DbaaS), Security-as-a-Service (SECaaS), Disaster recovery-as-a-Service (DRaaS), Communication-as-a-Service (CaaS), Networking-as-a-Service (NaaS), Managed Content-as-a-Service (MCaaS) and even daily activities like Transportation-as-a-Service (TaaS) and Healthcare-as-a-Service (HaaS). This only goes on to prove how important virtually managed services are going to become. As people become busier in their lives, they will tend more towards systems that will allow them to control those aspects of their life they cannot be present in physically at that moment, through a virtual mode of access. That is exactly the territory that -aaS services mean to fill.

Many subspecies of SaaS, PaaS and IaaS are also emerging, based on the differences in the needs of enterprises. The shift from on-premise infrastructure to cloud-based ones is stark and rapidly increasing. In fact, it is predicted that over 80% of businesses, big and small, will shift to cloud-based services by the end of 2020. As cloud-based services become more reliable and robust, enterprises will also become more confident in moving their data and operations from their traditional data centers to a virtual infrastructure. Projections for future years are also indicative of continuing growth and market shift towards business management solutions as well as customer services to a virtualized reality.

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