Short Q&A; for Cloud computing

As cloud computing has matured over the years, business potential of same has become quite mainstream. During its inception years, data privacy protection was a major concern for most of the giant corporates who weren't willing to move their data in someone else's environment but gradually models of cloud transformation evolved and momentum has now become a necessity to cut down costs of ownership.
I wrote about a short and crisp introduction on what cloud computing is and why does one need it in one of my earlier posts:

What is cloud computing?

Now in this post, I shall be focusing on putting more short questions and answers that are frequently asked during preliminary phases of interview process. Hope you find them useful:

Q1: What is Infrastructure As A Service (IaaS)? Give some examples.

A: IaaS is one specific category of cloud service which provides instant virtualized computing resources(Servers and storage that are hosted in data center physical plant/building made accessible through networking firewalls/security) over the internet.One can quickly scale up and pay as per use of service. The cloud computing service provider manages the infrastructure. Different example of IaaS are Amazon Web Services (AWS), Microsoft Azure, Google Compute Engine (GCE),Cisco Metapod,Linode, Rackspace, DigitalOcean etc.

Q2: What is Platform As A Service (PaaS) and what are layers of PaaS? Give some examples.

A: PaaS is one specific category of cloud service which provides a platform(OS+Development tools over infrastructure(data-centers consisting of  physical servers, network and security etc.)) which are available for a price over their web browsers for end users. Different examples of PaaS are AWS Elastic Beanstalk, Windows Azure, Heroku, Force.com, Google App Engine, Apache Stratos, OpenShift etc.

Q3: What is Software As A Service (SaaS)? Give some examples.
A: SaaS is one specific category of cloud service which provides software distribution model of third-party provided applications made accessible to customers over the Internet. SaaS runs on top of PaaS and IaaS combined. Different examples of SaaS are Google apps(Drive, Docs etc.), Dropbox, Cisco WebEx etc.

Q4: What are key differences in IaaS, PaaS and SaaS?

A:  The summary of key differences(self explanatory) in IaaS, PaaS and SaaS can be summarized in table given below:

Q5: What are the basic characteristics of cloud computing?

A: There are following basic characteristics of cloud computing:

        a. On-demand self-service: An end user can provision computing service automatically without requiring human interaction with each service provider. 

        b. Broad network access: services are available over the network and accessed through heterogeneous thin or thick client platforms (e.g., mobile phones, tablets, laptops, and workstations)

        c. Resource pooling: Multiple consumers using a multi-tenant model can be serviced in provider’s pooled environment dynamically. A consumer remains oblivious of exact location of the provided resources but may be able to specify location at a higher level of abstraction (e.g., country, state, or datacenter).Different resources include storage, processing, memory, and network bandwidth with different physical and virtual resources dynamically assigned and reassigned with demand.

        d. Rapid elasticity: Scale up/down rapidly and in specific cases automatically.

        e. Measured Service: Automatic control and optimize resources by leveraging a metering capability at some level of abstraction appropriate to the type of service (e.g., storage, processing, bandwidth, and active user accounts). Resource usage can be monitored, controlled, and reported, providing transparency for both the provider and consumer of the utilized service.

Q6: What are the must essentials to be followed before going to cloud computing platform?

A: Essentials are:

• Compliance issues
• Data storage types
• Data integrity adherence in the cloud
• Ensuring availability and access
• Protection from loss of data
• Business continuity plan
• Uptime - reduction of downtime  

Q7: What are different layers in cloud architecture?

A: A cloud computing architecture is consisted of following components:

• Front end: Fat client, thin client, mobile device
• Back end: Servers, Storages
• Cloud based delivery(IaaS, PaaS, SaaS)
• Network(Intranet, internet, inter-cloud) and Security

Q8: What are the types of data used in cloud computing?

A: Emails, images, videos, contracts, blogs etc.

Q9:How can our company benefit from cloud computing?

A:  The key cloud computing benefits are:

• Cost savings/Reduced OpEx
• Pay per use
• User defined security model for cloud computing(Private, Hybrid, Public clouds)
• Efforts and focus saved for more strategic initiatives of growth

Q10: How you can you best secure data while transporting in the cloud?

A:  A strong data encryption technique is a way before moving data across networks to storage servers/devices to eliminate chances of data leaks.

Q11: Explain the Security management in terms of Cloud Computing.

A:  There are two key pillars of security management of cloud computing:

 Identity management: Identify and manage personnels' data who can access authorized cloud based services. Define rules for authentication for these authorized personnels. 

Access management: Roles based access definition and management towards cloud based services

Q12: What is the difference between scalability and elasticity in cloud computing?

A: The scalability corresponds to growth seen in service capacity due to scale picked up by business demand while elasticity corresponds to flexiblity in system to commission or decommission resources capacity automatically/dynamically. 

Q13: What are hybrid clouds?

A:  A combination of public and private clouds is called hybrid cloud. It gives flexibility to organizations to decide what features or services they want to secure over others and take them to private cloud vs. rest to be put on public cloud.  

Q14: What is the difference between cloud computing and mobile computing? 

A:  Mobile computing inherently uses cloud computing and depends on it for data migration.