Basics of Cloud Computing

What is Cloud Computing?

Cloud Computing is usage of resources like Servers, Storage, Applications over the network hosted in the service provider data center with pay as use cost model, scale-up or scale down compute resources based on business need.

Here are definitions of Cloud Computing from Wiki, Microsoft and Amazon.

Wiki:

Cloud computing is shared pools of configurable computer system resources and higher-level services that can be rapidly provisioned with minimal management effort, often over the Internet. Cloud computing relies on sharing of resources to achieve coherence and economies of scale, similar to a public utility.

Microsoft: 

Cloud computing is the delivery of computing services—servers, storage, databases, networking, software, analytics, intelligence and more—over the Internet (“the cloud”) to offer faster innovation, flexible resources and economies of scale. You typically pay only for cloud services you use, helping lower your operating costs, run your infrastructure more efficiently and scale as your business needs change.

Amazon: 

Cloud computing is the on-demand delivery of compute power, database storage, applications, and other IT resources through a cloud services platform via the Internet with pay-as-you-go pricing.

Why Cloud Computing? 

Cloud computing is a buzz work these days, Organizations are aggressively adopting Cloud First Strategy to reap the benefits of Cloud.

Here are few benefits of Cloud Computing.

• Cost Reduction: No/Less Capital expenses, If organizations are moving completely to cloud, no Data-center running and management costs, no power and cooling cost and you pay to Cloud Service provider for what you use i.e., Pay as You Use model. Shifts Capital Expenses (CapEx) i.e., buying Servers, Storage Network etc., to Operating Expenses (OpEx) as you pay for what you use. 
• Rapid Speed: Provision and deploy Virtual Machines/Servers and Applications at great speed, with few mouse clicks VS few days or weeks with traditional models. 
• Productivity: Reduce the time it takes to Rack, Stack, Cable and Install Operating system to few minutes and Concentrate on productive stuff. 
• Scalability: Allows organizations to scale the resources CPU, Memory and Storage elastically with in the same location. 
• Security: Provides great security to Servers, Data and Applications with the Controls, Tools, Polices that organizations get from service providers. 

Key Players in Cloud Computing.

• Amazon Web Service (AWS) 
• Microsoft Azure. 
• Google Cloud Platform (GCP) 
• IBM 
• Alibaba 
• HP Enterprise. 
• VMware 
• Pivotal (Spin of EMC and VMware). 
• Oracle. 
• Sales Force. 

Types of Cloud

• Private Cloud: Infrastructure resources like Servers, Storage, Network and Virtualization are in Organization owned Data-center these are managed and supported by Staff with the Organization or outsourced vendors. 
• Public Cloud:Infrastructure resources like Servers, Storage, Network and Virtualization are in Service Provider owned Data-center these are managed Service Provider.
• Hybrid Cloud: Organization uses combination of both Public and Private Cloud Infrastructure

Private-Hybrid-Public

Cloud Services

Infrastucture as a Service (IaaS) : 

• Service Providers helps with Portal/APIs what will help us select and deploy infrastructure components, Operating System, Compute, Network and Location. 
• Resource are provided on demand. 
• We can Scale up/Scale Down, Scale-out, Scale-In. 
• Organization is responsible for Patching and Managing Operating System and installed Applications. 
• Pay as you use Billing (utility Based) for the resources allocated. 
• Virtual Machines, Storage, Network, Firewalls, Load-balancer etc. 
• Ex: Azure, AWS, Google, IBM etc. 

Platform as a Service (PaaS):

• Service Provides enables consumer/Organizations to Deploy and Manage Settings of the Applications. 
• Developers will develop, run applications. 
• Deployment Tool Kits will be provided by Service Providers. 
• Underlying Infra ( Hardware resources ) will scaleup automatically no intervention of developer needed. 
• Ex: Microsoft Azure, Windows Azure AppFabric, SQL Azure, Websites, Google App Service, OCP. 

Software as a Service (SaaS): 

• Service Provides enables consumer/Organizations to use Applications running on Cloud form client devices 
• Consumer/Organization will not manage Installed Apps, and underlying infrastructure. 
• Ex:Office 365, Google Apps, Webex, Citirx GotoMeeting etc. 

Below diagram explains who manages what in each Cloud Service Model.

IaaS-PaaS-SaaS