These services are divided into three main categories or types of cloud computing: infrastructure as a service (IaaS), platform as a service (PaaS) and software as a service (SaaS).
A cloud can be private or public. A public cloud sells services to anyone on the internet. A private cloud is a proprietary network or a data center that supplies hosted services to a limited number of people, with certain access and permissions settings. Private or public, the goal of cloud computing is to provide easy, scalable access to computing resources and IT services.
Cloud infrastructure involves the hardware and software components required for proper implementation of a cloud computing model. Cloud computing can also be thought of as utility computing or on-demand computing.
Types of cloud computing services
Cloud computing can be separated into three general service delivery categories or forms of cloud computing:
- IaaS. IaaS providers, such as Amazon Web Services (AWS), supply a virtual server instance and storage, as well as application programming interfaces (APIs) that let users migrate workloads to a virtual machine (VM). Users have an allocated storage capacity and can start, stop, access and configure the VM and storage as desired. IaaS providers offer small, medium, large, extra-large, and memory- or compute-optimized instances, in addition to enabling customization of instances, for various workload needs. The IaaS cloud model is closest to a remote data center for business users.
- PaaS. In the PaaS model, cloud providers host development tools on their infrastructures. Users access these tools over the internet using APIs, web portals or gateway software. PaaS is used for general software development, and many PaaS providers host the software after it’s developed. Common PaaS products include Salesforce’s Lightning Platform, AWS Elastic Beanstalk and Google App Engine.
- SaaS. SaaS is a distribution model that delivers software applications over the internet; these applications are often called web services. Users can access SaaS applications and services from any location using a computer or mobile device that has internet access. In the SaaS model, users gain access to application software and databases. One common example of a SaaS application is Microsoft 365 for productivity and email services.
Characteristics and advantages of cloud computing
Cloud computing has been around for several decades now, and today’s cloud computing infrastructure demonstrates an array of characteristics that have brought meaningful benefits for businesses of all sizes. Some of the main characteristics of cloud computing are the following:
- Self-service provisioning. End users can spin up compute resources for almost any type of workload on demand. An end user can provision computing capabilities, such as server time and network storage, eliminating the traditional need for IT administrators to provision and manage compute resources.
- Elasticity. Companies can freely scale up as computing needs increase and scale down again as demands decrease. This eliminates the need for massive investments in local infrastructure, which might or might not remain active.
- Pay per use. Compute resources are measured at a granular level, enabling users to pay only for the resources and workloads they use.
- Workload resilience. CSPs often implement redundant resources to ensure resilient storage and to keep users’ important workloads running — often across multiple global regions.
- Migration flexibility. Organizations can move certain workloads to or from the cloud — or to different cloud platforms — as desired or automatically for better cost savings or to use new services as they emerge.
- Broad network access. A user can access cloud data or upload data to the cloud from anywhere with an internet connection using any device.
- Multi-tenancy and resource pooling. Multi-tenancy lets numerous customers share the same physical infrastructures or the same applications yet still retain privacy and security over their own data. With resource pooling, cloud providers service numerous customers from the same physical resources. The resource pools of the cloud providers should be large and flexible enough so they can service the requirements of multiple customers.
Disadvantages of cloud computing
Despite the clear upsides to relying on cloud services, cloud computing carries its own challenges for IT professionals:
- Cloud security. Security is often considered the greatest challenge facing cloud computing. When relying on the cloud, organizations risk data breaches, hacking of APIs and interfaces, compromised credentials and authentication issues. Furthermore, there is a lack of transparency regarding how and where sensitive information entrusted to the cloud provider is handled. Security demands careful attention to cloud configurations and business policy and practice.
- Cost unpredictability. Pay-as-you-go subscription plans for cloud use, along with scaling resources to accommodate fluctuating workload demands, can make it tough to define and predict final costs. Cloud costs are also frequently interdependent, with one cloud service often utilizing one or more other cloud services — all of which appear in the recurring monthly bill. This can create additional unplanned cloud costs.
- Lack of capability and expertise. With cloud-supporting technologies rapidly advancing, organizations are struggling to keep up with the growing demand for tools and employees with the proper skill sets and knowledge needed to architect, deploy, and manage workloads and data in a cloud.
- IT governance. The emphasis on do-it-yourself capability in cloud computing can make IT governance difficult, as there is no control over provisioning, deprovisioning and management of infrastructure operations. This can make it challenging to properly manage risks and security, IT compliance and data quality.
- Compliance with industry laws. When transferring data from on-premises local storage into cloud storage, it can be difficult to manage compliance with industry regulations through a third party. It’s important to know where data and workloads are actually hosted in order to maintain regulatory compliance and proper business governance.
- Management of multiple clouds. Every cloud is different, so multi-cloud deployments can disjoint efforts to address more general cloud computing challenges.
- Cloud performance. Performance — such as latency — is largely beyond the control of the organization contracting cloud services with a provider. Network and provider outages can interfere with productivity and disrupt business processes if organizations are not prepared with contingency plans.
- Building a private cloud. Architecting, building and managing private clouds — whether for its own purpose or for a hybrid cloud goal — can be a daunting task for IT departments and staff.
- Cloud migration. The process of moving applications and other data to a cloud infrastructure often causes complications. Migration projects frequently take longer than anticipated and go over budget. The issue of workload and data repatriation — moving from the cloud back to a local data center — is often overlooked until unforeseen cost or performance problems arise.
- Vendor lock-in. Often, switching between cloud providers can cause significant issues. This includes technical incompatibilities, legal and regulatory limitations and substantial costs incurred from sizable data migrations.
Cloud computing examples and use cases
Cloud computing has evolved and diversified into a wide array of offerings and capabilities designed to suit almost any conceivable business need. Examples of cloud computing capabilities and diversity include the following:
- Google Docs, Microsoft 365. Users can access Google Docs and Microsoft 365 through the internet. Users can be more productive because they can access work presentations and spreadsheets stored in the cloud at anytime from anywhere on any device.
- Email, Calendar, Skype, WhatsApp. Emails, calendars, Skype and WhatsApp take advantage of the cloud’s ability to provide users with access to data remotely so they can access their personal data on any device, whenever and wherever they want.
- Zoom. Zoom is a cloud-based software platform for video and audio conferencing that records meetings and saves them to the cloud, enabling users to access them anywhere and at any time. Another common communication and collaboration platform is Microsoft Teams.
- AWS Lambda. Lambda enables developers to run code for applications or back-end services without having to provision or manage servers. The pay-as-you-go model constantly scales with an organization to accommodate real-time changes in data usage and data storage. Other major cloud providers also support serverless computing capabilities, such as Google Cloud Functions and Azure Functions.
So, how is the cloud actually used? The myriad services and capabilities found in modern public clouds have been applied across countless use cases, such as the following:
- Testing and development. Ready-made, tailored environments can expedite timelines and milestones.
- Production workload hosting. Organizations are using the public cloud to host live production workloads. This requires careful design and architecture of cloud resources and services needed to create an adequate operational environment for the workload and its required level of resilience.
- Big data analytics. Remote data centers through cloud storage are flexible and scalable and can provide valuable data-driven insights. Major cloud providers offer services tailored to big data projects, such as Amazon EMR and Google Cloud Dataproc.
- IaaS. IaaS enables companies to host IT infrastructures and access compute, storage and network capabilities in a scalable manner. Pay-as-you-go subscription models can help companies save on upfront IT costs.
- PaaS. PaaS can help companies develop, run and manage applications in an easier and more flexible way, at a lower cost than maintaining a platform on premises. PaaS services can also increase development speed for applications and enables higher-level programming.
- Hybrid cloud. Organizations have the option to use the appropriate cloud — private or public — for different workloads and applications to optimize cost and efficiency according to the circumstance.
- Multi-cloud. Using multiple different cloud services from separate cloud providers can help subscribers find the best cloud service fit for diverse workloads with specific requirements.
- Storage. Large amounts of data can be stored remotely and accessed easily. Clients only have to pay for storage that they actually use.
- DR. Cloud offers faster recovery than traditional on-premises DR. Furthermore, it is offered at lower costs.
- Data backup. Cloud backup solutions are generally easier to use. Users do not have to worry about availability and capacity, and the cloud provider manages data security.
Cloud computing vs. traditional web hosting
Given the many different services and capabilities of the public cloud, there has been some confusion between cloud computing and major uses, such as web hosting. While the public cloud is often used for web hosting, the two are quite different. A cloud service has three distinct characteristics that differentiate it from traditional web hosting:
- Users can access large amounts of computing power on demand. It is typically sold by the minute or the hour.
- It is elastic — users can have as much or as little of a service as they want at any given time.
- The service is fully managed by the provider — the consumer needs nothing but a personal computer and internet access. Significant innovations in virtualization and distributed computing, as well as improved access to high-speed internet, have accelerated interest in cloud computing.