Cloud computing is a complex and evolving process. It is a process of creating a cloud service that can be used to provide a service to a consumer. The need for cloud services is different for different consumers. For example, a consumer may need a cloud service that can be used just to keep track of his financial expenses. Like that another consumer may need the whole virtual machine to perform complex tasks.
Based on the need of the consumers, or more accurately the types of service provided by a cloud vendor, cloud service model can be divided into mainly three parts.
IaaS is the type of service model where the consumer gets the most flexibility and control over the infrastructure. The services provided by a vendor might be storage, networking, servers or other computational resources. Most of the time, this service works on the pay-as-you-use model. The vendor manages the underlying infrastructure like virtualization, storage, and networking. The vendor also manages the security of the underlying infrastructure. The consumer manages the OS, data, applications etc.
In IaaS, the consumer can customize the infrastructure to his needs by himself. In some cases, the consumer might need sufficient knowledge about networking, storage, database, user management, and so on. In IaaS, the vendor has the least control over the security. So, the consumer should take care of that also. Although the consumer gets the most flexibility, it's not the most suitable for all the consumers.
- Upfront cost: The upfront cost of IaaS is less than the upfront cost of on-premises IT infrastructure.
- Security: The vendor has the least control over the security.
- Scalability Consumers can scale-up or scale-down the services as needed.
- No single point of failure: There can be no single point of failure as the data is stored in the cloud.
- Security: As all the services are stored in the cloud, the vendor has no control over the security of the underlying infrastructure.
- Legacy applications: Legacy applications might create issues on the migration as some applications are not compatible with the cloud infrastructure.
- Cost in long-term: The cost of IaaS might go higher than the on-premises infrastructure in the long term.
Examples of IaaS
When to Use IaaS
- IaaS is suitable for all kinds of businesses.
- Small companies can use IaaS to save the upfront cost.
- Large enterprises can use IaaS to have full control over the application and the infrastructure.
In PaaS, the vendor provides consumers with a cloud environment where they can develop, manage, and deliver their applications. The vendor manages most of the infrastructures, from runtime to networking so that the consumer can focus on the application development.
- Platform: PaaS provides a platform to create, manage and deliver applications.
- Managed infrastructure Consumers do not need to worry about the underlying infrastructure.
- Easy migration PaaS provides easy migration to the hybrid model.
- Runtime issues: There might be runtime issues associated with specific applications.
- Integration: Consumers might encounter difficulties when integrating a new application.
- Operational limitations: Customized automated operational workflow might not work with PaaS.
Examples of PaaS
When to Use PaaS
- PaaS can be used to develop and deploy applications faster.
SaaS is an application service model where the consumer accesses the vendor's cloud-based application from a web browser or an API. Consumers do not have to manage the infrastructure, security, or any other aspects of the cloud. The vendor manages the application and the security.
- Easy access: SaaS applications can easily be accessed by a web browser or an API.
- Scalability: SaaS applications can be scaled-up or scaled-down as needed by the vendor.
- Security: The vendor provides the highest security out of all the service models.
- Security: The vendor has no control over the security of the application and the underlying infrastructure.
- Interoperability: Integration with the services of different vendors or existing applications might not work if the SaaS application is not designed for open integration.
- Customization: SaaS applications allow no or minimal customization.
Examples of SaaS
When to Use SaaS
- SaaS is suitable for scenarios where consumers want less effort on management of the application.
- SaaS applications are very cost effective. So, SaaS is ideal for small businesses.
- "IaaS vs. PaaS vs. SaaS - India | IBM" Ibm, 10 Oct. 2018, https://www.ibm.com/in-en/cloud/learn/iaas-paas-saas.
- Watts, Stephen, et al. ""SaaS vs PaaS vs IaaS: What’s The Difference & How To Choose – BMC Software | Blogs" Bmc, 15 Jun. 2019, https://www.bmc.com/blogs/saas-vs-paas-vs-iaas-whats-the-difference-and-how-to-choose/.
- "SaaS vs. PaaS vs. IaaS: Examples & How to Tell Them Apart | BigCommerce" Bigcommerce, https://www.bigcommerce.com/articles/ecommerce/saas-vs-paas-vs-iaas/.