Previously we have discussed the types of cloud computing. But have you ever wondered what are the services provided through cloud computing? You know that cloud computing is an advancement of your traditional data centers services. When we say that this is advanced, it’s pretty sure that through cloud services you should get all the services the same as your existing data center with some additional features. So generally the cloud computing is serving the users through 3 different service models as below,

• IaaS – Infrastructure as a service
• PaaS – Platform as a service
• SaaS – Software as a service

Each of these has its own benefits, as well as variances, and it is necessary to understand the differences between SaaS, PaaS, and IaaS to know how to best choose one for your organization. What are the services provided by each of this service is simply existing on its name itself? Let me give you a small picture clarification that can give you a full idea in a stretch.

So let’s take a deep look into each of it.

IaaS – Infrastructure as a service

In the simplest form, IaaS services will give you a complete IT infrastructure for you to host your data or software. From the bottom up, Infrastructure as a Service (IaaS) delivers a computing infrastructure in a virtualized environment. These infrastructure resources include virtual compute and storage resources, bandwidth, network connections and more. IaaS can scale up and down as demand changes and also provide redundancy configurations to ensure high availability.

IaaS allows businesses to purchase resources on-demand and as-needed instead of having to buy hardware outright. The cloud provider maintains the servers and networks in the data centers, assuming responsibility for all physical equipment. Security is a joint responsibility with the Shared Responsibility Model. The customer’s IT is responsible for the configuration and maintenance of the guest operating systems, related applications, and resources. As companies embrace different cloud infrastructure models, IT may have to integrate public, private, multi-provider and on-premise environments.

Some of the examples for this service model is Rackspace, Amazon Web Services (AWS), Microsoft Azure, Google Compute Engine (GCE), Oracle OCI.

IaaS Advantages

• The most flexible cloud computing model
• Easy to automate deployment of storage, networking, servers, and processing power
• Hardware purchases can be based on consumption
• Resources can be purchased as-needed
• Highly scalable
• Resources are available as a service
• Services are highly scalable
• Organization retain complete control of the infrastructure
• Dynamic and flexible

IaaS Limitations

• Legacy systems operating in the cloud. While customers can run legacy apps in the cloud, the infrastructure may not be designed to deliver specific controls to secure the legacy apps. Minor enhancement to legacy apps may be required before migrating them to the cloud, possibly leading to new security issues unless adequately tested for security and performance in the IaaS systems.
• Internal resources and training – Additional resources and training may be required for the workforce to learn how to effectively manage the infrastructure. Customers will be responsible for data security, backup, and business continuity. Due to inadequate control into the infrastructure however, monitoring and management of the resources may be difficult without adequate training and resources available inhouse.
• While the customer is in control of the apps, data, middleware, and the OS platform, security threats can still be sourced from the host or other virtual machines (VMs). Insider threat or system vulnerabilities may expose data communication between the host infrastructure and VMs to unauthorized entities.
• Multi-tenant security – Since the hardware resources are dynamically allocated across users as made available, the vendor is required to ensure that other customers cannot access data deposited to storage assets by previous customers. Similarly, customers must rely on the vendor to ensure that VMs are adequately isolated within the multitenant cloud architecture. 

PaaS – Platform as a service

Platform as a Service (PaaS) expands on the capabilities of the SaaS model by not only delivering software but also providing the platform for software development with databases, storage, web servers, and operating systems. It is located in-between the SaaS and IaaS layers, supplying more than the bare infrastructure but not the full-fledged application. The PaaS layer provides developers with tools such as business process management, database, and integrations. With this platform, they can develop, run and manage their applications. For businesses who are proficient in IaaS but want the agility and flexibility of PaaS, being able to utilize both layers is an advantage.

Some of the examples for this service model is AWS Elastic Beanstalk, Salesforce, Google App Engine, Apache Stratos, OpenShift, Visual Builder.

PaaS Advantages

• Simple, cost-effective development and deployment of apps
• Scalable
• Highly available
• Developers can customize apps without the headache of maintaining the software
• Significant reduction in the amount of coding needed
• Builds on virtualization technology, so resources can easily be scaled up or down as your business changes
• Provides a variety of services to assist with the development, testing, and deployment of apps
• Accessible to numerous users via the same development application
• Integrates web services and databases

PaaS Limitations

• The complexity of connecting the data stored within an onsite data center or off-premise cloud is increased, which may affect which apps and services can be adopted with the PaaS offering. Particularly when not every component of a legacy IT system is built for the cloud, integration with existing services and infrastructure may be a challenge.
• Vendor lock-in. Business and technical requirements that drive decisions for a specific PaaS solution may not apply in the future. If the vendor has not provisioned convenient migration policies, switching to alternative PaaS options may not be possible without affecting the business.
• Customization of legacy systems. PaaS may not be a plug-and-play solution for existing legacy apps and services. Instead, several customizations and configuration changes may be necessary for legacy systems to work with the PaaS service. The resulting customization can result in a complex IT system that may limit the value of the PaaS investment altogether.
• Runtime issues. In addition to limitations associated with specific apps and services, PaaS solutions may not be optimized for the language and frameworks of your choice. Specific framework versions may not be available or perform optimally with the PaaS service. Customers may not be able to develop custom dependencies with the platform.

SaaS – Software as a service

In a SaaS service model, the applications will be readily available for customers to use. These are preinstalled and predeveloped applications by different software vendors. With SaaS, the cloud service provider hosts the software and associated data and the user consumes the application on demand. Due to ease of entry, small companies now have the ability to use applications that were previously only available for larger businesses. As the mobile workforce continues to grow, SaaS helps to guarantee a similar experience for all users.

Some of the examples for this service model are Oracle Fusion, Microsoft O365, Google G-suit and GoToMeeting.

SaaS provides numerous advantages to employees and companies by greatly reducing the time and money spent on tedious tasks such as installing, managing, and upgrading software.

SaaS Advantages

• Accessible over the internet.
• Less IT administrative capability is required as compared to the other two service models.
• Users are not responsible for hardware or software updates.
• Frees up plenty of time for technical staff to spend on more pressing matters and issues within the organization.
• Managed from a central location by SAAS provider.
• Ongoing involvement is greatly reduced, as expertise is no longer required to the same degree to configure and manage applications, conduct software upgrades, install patches, and integrate APIs.
• Startups or small companies that need to launch e-commerce quickly and don’t have time for server issues or software.
• SaaS application’s security and features would be high since this will be updated SaaS providers on a timely manner.

SaaS Limitations

• Vendor lock-in. Vendors may make it easy to join a service and difficult to get out of it. For instance, the data may not be portable–technically or cost-effectively–across SaaS apps from other vendors without incurring significant cost or inhouse engineering rework. Not every vendor follows standard APIs, protocols, and tools, yet the features could be necessary for certain business tasks.
• Lack of integration support. Many organizations require deep integrations with on-premise apps, data, and services. The SaaS vendor may offer limited support in this regard, forcing organizations to invest internal resources in designing and managing integrations. The complexity of integrations can further limit how the SaaS app or other dependent services can be used.
• SaaS apps offer minimal customization capabilities. Since a one-size-fits-all solution does not exist, users may be limited to specific functionality, performance, and integrations as offered by the vendor. In contrast, on-premise solutions that come with several software development kits (SDKs) offer a high degree of customization options.
• Lack of control. SaaS solutions involve handing control over to the third-party service provider. These controls are not limited to the software–in terms of the version, updates, or appearance–but also the data and governance. Customers may, therefore, need to redefine their data security and governance models to fit the features and functionality of the SaaS service.
• Integration with existing apps and services can be a major concern if the SaaS app is not designed to follow open standards for integration. In this case, organizations may need to design their own integration systems or reduce dependencies with SaaS services, which may not always be possible.
• Data security. Large volumes of data may have to be exchanged to the backend data centers of SaaS apps in order to perform the necessary software functionality. Transferring sensitive business information to public-cloud based SaaS service may result in compromised security and compliance in addition to significant cost for migrating large data workloads.

SaaS vs PaaS vs IaaS

Each cloud model offers specific features and functionalities, and it is crucial for your organization to understand the differences. Whether you need cloud-based software for storage options, a smooth platform that allows you to create customized applications or complete control over your entire infrastructure without having to physically maintain it, there is a cloud service for you. No matter which option you choose, migrating to the cloud is the future of business and technology.

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