What is cloud computing?

Ayush Gupta
12 min readSep 22, 2020

Cloud computing is on-demand access, via the internet, to computing resources — applications, servers (physical servers and virtual servers), data storage, development tools, networking capabilities, and more — hosted at a remote data center managed by a cloud services provider. The cloud services provider makes these resources available for a monthly subscription fee or bills them according to usage.

Compared to traditional on-premises IT, and depending on the cloud services you select, cloud computing helps do the following:

  • Lower IT costs: Cloud lets you offload some or most of the costs and effort of purchasing, installing, configuring, and managing your own on-premises infrastructure.
  • Improve agility and time-to-value: With cloud, your organization can start using enterprise applications in minutes, instead of waiting weeks or months for IT to respond to a request, purchase and configure supporting hardware, and install software. Cloud also lets you empower certain users — specifically developers and data scientists — to help themselves to software and support infrastructure.
  • Scale more easily and cost-effectively: Cloud provides elasticity — instead of purchasing excess capacity that sits unused during slow periods, you can scale capacity up and down in response to spikes and dips in traffic. You can also take advantage of your cloud provider’s global network to spread your applications closer to users around the world.

The term ‘cloud computing’ also refers to the technology that makes cloud work. This includes some form of virtualized IT infrastructure — servers, operating system software, networking, and other infrastructure that’s abstracted, using special software, so that it can be pooled and divided irrespective of physical hardware boundaries. For example, a single hardware server can be divided into multiple virtual servers.

Virtualization enables cloud providers to make maximum use of their data center resources. Not surprisingly, many corporations have adopted the cloud delivery model for their on-premises infrastructure so they can realize maximum utilization and cost savings vs. traditional IT infrastructure and offer the same self-service and agility to their end-users.

If you use a computer or mobile device at home or at work, you almost certainly use some form of cloud computing every day, whether it’s a cloud application like Google Gmail or Salesforce, streaming media like Netflix, or cloud file storage like Dropbox. According to a recent survey, 92% of organizations use cloud today (outside link), and most of them plan to use it more within the next year.

Now, Let’s get dive into the History of Cloud : →

Features of Cloud Computing :—

As cloud computing services mature both commercially and technologically, it will be easier for companies to maximize the potential benefits. Knowing what cloud computing is and what it does, however, is just as important. The National Institute of Standards and Technology (NIST) defines cloud computing as it is known today through five particular characteristics.

1. On-demand self-service

Cloud computing resources can be provisioned without human interaction from the service provider. In other words, a manufacturing organization can provision additional computing resources as needed without going through the cloud service provider. This can be a storage space, virtual machine instances, database instances, and so on.

Manufacturing organizations can use a web self-service portal as an interface to access their cloud accounts to see their cloud services, their usage, and also to provision and re-provision services as they need to.

2. Broad network access

Cloud computing resources are available over the network and can be accessed by diverse customer platforms. It other words, cloud services are available over a network — ideally high broadband communication link — such as the internet, or in the case of a private clouds it could be a local area network (LAN).

Network bandwidth and latency are very important aspects of cloud computing and broad network access, because they relate to the quality of service (QoS) on the network. This is particularly important for serving time sensitive manufacturing applications.

3. Multi-tenancy and resource pooling

Cloud computing resources are designed to support a multi-tenant model. Multi-tenancy allows multiple customers to share the same applications or the same physical infrastructure while retaining privacy and security over their information. It’s similar to people living in an apartment building, sharing the same building infrastructure but they still have their own apartments and privacy within that infrastructure. That is how cloud multi-tenancy works.

Resource pooling means that multiple customers are serviced from the same physical resources. Providers’ resource pool should be very large and flexible enough to service multiple client requirements and to provide for economy of scale. When it comes to resource pooling, resource allocation must not impact performances of critical manufacturing applications.


SaaS (Software-as-a-Service)

SaaS — also known as cloud-based software or cloud applications — is application software that’s hosted in the cloud and that you access and use via a web browser, a dedicated desktop client, or an API that integrates with your desktop or mobile operating system. In most cases, SaaS users pay a monthly or annual subscription fee; some may offer ‘pay-as-you-go’ pricing based on your actual usage.

SaaS provides you with a complete product that is run and managed by the service provider. In most cases, people referring to SaaS are referring to end-user applications (such as web-based email). With a SaaS offering, you don’t have to think about how the service is maintained or how the underlying infrastructure is managed. You only need to think about how you will use that particular software.

In addition to the cost savings, time-to-value, and scalability benefits of cloud, SaaS offers the following:

  • Automatic upgrades: With SaaS, you take advantage of new features as soon as the provider adds them, without having to orchestrate an on-premises upgrade.
  • Protection from data loss: Because your application data is in the cloud, with the application, you don’t lose data if your device crashes or breaks

PaaS (Platform-as-a-Service)

PaaS provides software developers with on-demand platform — hardware, complete software stack, infrastructure, and even development tools — for running, developing, and managing applications without the cost, complexity, and inflexibility of maintaining that platform on-premises.

With PaaS, the cloud provider hosts everything — servers, networks, storage, operating system software, middle-ware, databases — at their data center. Developers simply pick from a menu to ‘spin up’ servers and environments they need to run, build, test, deploy, maintain, update, and scale applications.

Today, PaaS is often built around containers, a virtualized compute model one step removed from virtual servers. Containers virtualize the operating system, enabling developers to package the application with only the operating system services it needs to run on any platform, without modification and without need for middle-ware.

Red Hat Open Shift is a popular PaaS built around Docker containers and Kubernetes, an open source container orchestration solution that automates deployment, scaling, load balancing, and more for container-based applications.

IaaS (Infrastructure-as-a-Service)

IaaS provides on-demand access to fundamental computing resources–physical and virtual servers, networking, and storage — over the internet on a pay-as-you-go basis. IaaS enables end users to scale and shrink resources on an as-needed basis, reducing the need for high, up-front capital expenditures or unnecessary on-premises or ‘owned’ infrastructure and for overbuying resources to accommodate periodic spikes in usage.

IaaS contains the basic building blocks for cloud IT. It typically provides access to networking features, computers (virtual or on dedicated hardware), and data storage space. IaaS gives you the highest level of flexibility and management control over your IT resources. It is most similar to the existing IT resources with which many IT departments and developers are familiar.

In contrast to SaaS and PaaS (and even newer PaaS computing models such as containers and server-less), IaaS provides the users with the lowest-level control of computing resources in the cloud.

IaaS was the most popular cloud computing model when it emerged in the early 2010. While it remains the cloud model for many types of workloads, use of SaaS and PaaS is growing at a much faster rate.

→ We also have one more kind of service

Server-less computing

Server-less computing (also called simply server-less) is a cloud computing model that offloads all the back-end infrastructure management tasks–provisioning, scaling, scheduling, patching — to the cloud provider, freeing developers to focus all their time and effort on the code and business logic specific to their applications.

FaaS, or Function-as-a-Service, is often confused with server-less computing when, in fact, it’s a subset of server-less. FaaS allows developers to execute portions of application code (called functions) in response to specific events. Everything besides the code — physical hardware, virtual machine operating system, and web server software management — is provisioned automatically by the cloud service provider in real-time as the code executes and is spun back down once the execution completes. Billing starts when execution starts and stops when execution stops.

Types of Cloud Computing

Cloud security

Traditionally, security concerns have been the primary obstacle for organizations considering cloud services, particularly public cloud services. In response to demand, however, the security offered by cloud service providers is steadily outstripping on-premises security solutions.

According to security software provider McAfee, today, 52% of companies experience better security in the cloud than on-premises (outside link). And Gartner has predicted that by this year (2020), infrastructure as a service (IaaS) cloud workloads will experience 60% fewer security incidents than those in traditional data centers (outside link).

Nevertheless, maintaining cloud security demands different procedures and employee skill sets than in legacy IT environments. Some cloud security best practices include the following:

Cloud Computing Market

As per above statics amazon web services covers the max. market stats, as aws provides best services in terms of cloud computing the billing criteria is unique.

So Looking at this wonderful stats shown by amazon let’s discuss an interesting use case solved by aws for most popular show channel “DISCOVERY CHANNEL”.

Discovery Channel (known as The Discovery Channel from 1985 to 1995, and often referred to as simply Discovery) is an American multinational pay television network and flagship channel owned by Discovery, Inc., a publicly traded company run by CEO David Zaslav.

Discovery Communications Case Study


Discovery Communications (Nasdaq: DISCA, DISCB, DISCK) is a leader in nonfiction media, reaching more than 1.8 billion cumulative subscribers in 218 countries and territories. Discovery is dedicated to satisfying curiosity through 155 worldwide television networks, led by Discovery Channel, TLC, Animal Planet, Science and Investigation Discovery, as well as US joint venture networks OWN: Oprah Winfrey Network, The Hub and 3net, the first 24-hour 3D network. Discovery also is a leading provider of educational products and services to schools and owns and operates a diversified portfolio of digital media services, including Revision3.

We migrated more than 40 sites to AWS without missing a beat. We now host all our digital media on AWS. Using the AWS Cloud gives us great capacity to expand or shrink our infrastructure as business requirements change — we now have an easy way to re-architect any of our sites.”

Igor Brezac
Chief Systems Architect, Digital Media, Discovery Communications

The Challenge

Discovery needed to upgrade its website infrastructure, but wanted to avoid a costly upfront one-time expense for updating their hardware. Upgrading would have taken considerable time to accomplish for a three-person team from Discovery Communications, between acquiring the hardware, configuring it, and migrating data to the new system. Discovery also had multiple delivery engines powering their websites, and wanted to consolidate to make their infrastructure easier to manage. Furthermore, the company needed a solution that would allow them the flexibility to pay for only what they used, and the ability to scale quickly to meet demand.

Why Amazon Web Services

Discovery assessed multiple cloud solutions, but none offered the flexibility and pricing of Amazon Web Services (AWS). “AWS was the most mature offering available,” says Igor Brezac, Chief Systems Architect, Digital Media. “The pricing was excellent. We were also attracted by the ability to get new instances up and running at a moment’s notice.” Discovery is now running all of its services on AWS for its US-based digital properties.

  1. Discovery Communications is running about 150 instances of Amazon Elastic Compute Cloud (Amazon EC2), all of which use Amazon Elastic Block Service (Amazon EBS) storage.
  2. Discovery uses Amazon Machine Images (AMI) that are built with a custom version of Ubuntu.
  3. Elastic Load Balancing (Amazon ELB) handles load balancing both externally and internally for Discovery, inside the Amazon Virtual Private Cloud (Amazon VPC).
  4. The company uses Amazon Simple Storage Service (Amazon S3) to store static content and host a few websites.
  5. Discovery also uses Amazon Route 53 in combination with Amazon ELB for its domain name service.
  6. Discovery’s static assets are delivered globally by Amazon CloudFront’s distributed edge servers. In addition, Discovery also uses Amazon CloudFront’s dynamic content acceleration feature for services like image resizing service and the new Discovery website. “Having a content delivery network (CDN) that delivers both static and dynamic content, including API acceleration, was important to us,” Brezac says.
  7. The use of Multiple Availability Zones (Multi-AZ) has also played a role in Discovery’s success. “This is where Amazon ELB is vital to us,” Brezac continues. “If one Availability Zone is unavailable, Amazon ELB will send the traffic to the other data center. Amazon Multi-AZ is key to the entire deployment. Without that, we wouldn’t have the peace of mind that we do.”

The Benefits

Discovery began implementing AWS in January 2012, and completed site migration in June 2013. “We migrated more than 40 sites to AWS without missing a beat,” Brezac says. “We now host all our digital media on AWS. Using the AWS Cloud gives us great capacity to expand or shrink our infrastructure as business requirements change — we now have an easy way to re-architect any of our sites.”

“Without AWS, it would be harder to focus on business initiatives without having to manage hardware and infrastructure,” Brezac said. In addition, the Digital Media division has evolved from administrators to system engineers, growing their skills and providing more benefit to the company.

Discovery Communications particularly values the horizontal scaling that AWS makes possible. “We’re able to scale to each part of the stack horizontally,” says Eric Connell, Senior Systems Engineer. “So if we’re running out of capacity in any piece of the stack, that piece of the stack automatically scales up to increase capacity.”

“Without using the AWS API and services, we wouldn’t be able to provide our staff with the tools we do,” concludes Shawn Stratton, Senior Systems Engineer/Architect. “Our entire continuous delivery system and our development platform are built around using the AWS API.”

Discovery uses CDNs for static, dynamic and API delivery. “Amazon CloudFront was able to offer us the scalability and low latency we expect from a CDN with cost savings of 20–25 percent and better manageability,” Brezac says. “Amazon CloudFront APIs and tight integration with other services like Amazon S3, Elastic Load Balancing, and Amazon Route 53 have helped us easily get started and manage our content delivery.

AWS Services Used

Amazon EC2

Amazon Elastic Compute Cloud (Amazon EC2) is a web service that provides secure, resizable compute capacity in the cloud. It is designed to make web-scale cloud computing easier for developers.

Amazon VPC

Amazon Virtual Private Cloud (Amazon VPC) lets you provision a logically isolated section of the AWS Cloud where you can launch AWS resources in a virtual network that you define.

Amazon EBS

Amazon Elastic Block Store (EBS) is an easy to use, high performance block storage service designed for use with Amazon Elastic Compute Cloud (EC2) for both throughput and transaction intensive workloads at any scale.

Amazon S3

Amazon Simple Storage Service (Amazon S3) is an object storage service that offers industry-leading scalability, data availability, security, and performance.

Amazon Machine Images

The Amazon Linux AMI is a supported and maintained Linux image provided by Amazon Web Services for use on Amazon Elastic Compute Cloud (Amazon EC2).

Amazon Route 53

Amazon Route 53 is a highly available and scalable cloud Domain Name System (DNS) web service.

Amazon ELB

Elastic Load Balancing automatically distributes incoming application traffic across multiple targets, such as Amazon EC2 instances, containers, IP addresses, and Lambda functions.

Amazon CloudFront

Amazon CloudFront is a fast content delivery network (CDN) service that securely delivers data, videos, applications, and APIs to customers globally with low latency, high transfer speeds, all within a developer-friendly environment.