What and Why Cloud Computing ?

Blog 1 . 23rd August 2021

Vishara Prabuddhi

Published in

MS Club of SLIIT

5 min readAug 23, 2021

What is Cloud Computing?

Cloud computing is the delivery of computing services (especially data storage and computing power) over the Internet.

Examples for Cloud Computing services

Storage, Databases, Servers, Networking, Software, Analytics, Intelligence

Benefits of Cloud Computing

High availability — There are vast amount of cloud services on demand. It provides the user a continuous user experience with no apparent downtime.

Cost-effectiveness — This helps to get rid of the capital expense of buying software and hardware resources, and maintenance.

Scalability — The user can have the right amount of resources when they are needed, and they can increase the compute capacity at any time.

Auto-scaling — This enables to scale cloud services such as server capacity or virtual machines up or down automatically.

Disaster recovery — Cloud-based backup services help to recover lost data at any time.

Main 3 types of deployment models in cloud computing.

Public Cloud

Public cloud delivered through the public internet and are available to anyone who wants to purchase them. It is offered as paid subscription or free of charge. Public clouds are owned and operated by a third-party cloud service provider. In this all hardware, software, and other supporting infrastructure is owned and managed by the third-party cloud service provider. Therefore public cloud, no need of capital expenditure to scale up, and the users have to pay only for what they use.

Private Cloud

Private cloud refers to cloud computing resources operated solely for a single business or an organization. It is managed internally or by a third-party cloud service provider, and hosted either internally (physically located at the organization’s on-site / on-premises data centers) or externally (hosted by the third-party service provider). In this case, hardware must be purchase at the beginning and while maintenance, and the user is responsible for hardware maintenance and update. User has the complete control over resources and security.

Hybrid Cloud

A hybrid cloud is a computing environment, which is a combination of public clouds and private clouds bound together by technology to allow data and applications to be shared between them. This provides the most flexibility. In this case, the users determine where to run their applications, and they can control security, compliance, or legal requirements.

Main 3 types of cloud services: IaaS, PaaS, and SaaS

Infrastructure as a service (IaaS)

This is the most basic category of cloud computing services. IaaS offers essential compute, storage, and networking resources (IT infrastructures) on-demand, on a pay-as-you-go basis. IaaS solutions help the user to reduce maintenance of on-premises data centers, save money on hardware costs, and gain real-time business insights. IaaS solutions give you the flexibility to scale your IT resources up and down with demand. They also help you quickly provision new applications and increase the reliability of your underlying infrastructure.

Platform as a service (PaaS)

PaaS is a managed hosting environment that supplies an on-demand environment for developing, testing, delivering, and managing software applications. PaaS is designed to make it easier for developers to quickly create web or mobile apps, without worrying about setting up or managing the underlying infrastructure of servers, storage, network resources, and databases needed for development.

PaaS allows the user to avoid the expense and complexity of buying and managing software licenses, the underlying application infrastructure and middleware, or the development tools and other resources. The user manages the applications and services they develop, and the cloud service provider typically manages everything else.

Software as a service (SaaS)

Software as a service is a method for delivering software applications over the Internet, on demand and typically on a subscription basis. In this, the cloud provider manages all aspects of the application environment, such as virtual machines, networking resources, data storage, and applications. The user only needs to provide their data to the application managed by the cloud provider. The cloud providers handle any maintenance, like software upgrades and security patching. Common examples are email, calendaring, and office tools (such as Microsoft Office 365).

SaaS provides a complete software solution that you purchase on a pay-as-you-go basis from a cloud service provider. The users rent the use of an app, and they connect to it over the Internet, usually with a web browser. All of the underlying infrastructure, middleware, app software, and app data are located in the service provider’s data center. The service provider manages the hardware and software, and with the appropriate service agreement, will ensure the availability and the security of the app and the data as well. SaaS allows the user to get quickly up and running with an app at minimal upfront cost.