Define Cloud Computing

Cloud computing can be defined as a mechanism to access applications that actually reside at a location other than your computer.  As per definition it is most often another Internet-connected device in a distant data center. Under this paradigm another company hosts your applications rather than you doing it yourself. This means that they handle the costs of servers and also manage any software updates.

Cloud Computing Architecture


These are the terminals used to access various cloud computing services. The terminals connect to the cloud via regular internet or network connection.

Data Center

It is the collection of servers where the cloud application to which you subscribe is housed.The servers could be distributed anywhere in the world but all that complexity will be hidden from the user.

Cloud Computing Infrastructure

Grid Computing

Grid computing applies the resources of numerous computers in a network to work on a single problem at the same time. It provides a cost-effective way to use a given amount of computer resources as the resources of several computers can be shared cooperatively.

Full virtualization

Full virtualization is a technique in which a complete installation of one machine is run on another. The result is a system in which all software running on the server is within a virtual machine. It helps emulating a particular hardware on another machine and allows sharing a computer system among multiple users and isolating users from each other and from the control program. Here  a type-2 hypervisor (hosted virtual machine manager run within a conventional operating system environment) is used to partially allow access to the hardware and partially to simulate hardware in order to allow you to load a full operating system. This is used by emulation packages like VMware Server, Workstation, Virtual PC, and Virtual Server.


Paravirtualization allows multiple operating systems to run on a single hardware device at the same time by more efficiently using system resources, like processors and memory. Here the guest operating systems run on the hypervisor, allowing for higher performance and efficiency.  Examples of this are Microsoft Hyper-V and VMware ESX Server.

Full virtualization Vs Paravirtualization

In full virtualization, the entire system is emulated (BIOS, drive, etc), but in paravirtualization, its management module operates with an operating system that has been adjusted to work in a virtual machine. Paravirtualization typically runs better than the full virtualization model, simply because in a fully virtualized deployment, all elements must be emulated.

Cloud Computing Services

Software as a Service

Software as a Service (SaaS) is the model in which an application is hosted as a service to customers who access it via the Internet.

Platform as a Service

Platform as a Service (PaaS) supplies all the resources required to build applications and services completely from the Internet, without having to download or install software. However vendors use proprietary services or development languages this may cause customers to be locked into a single provider. The vendor may allow the application to be brought to a different provider; however, the costs are typically higher as compared to moving applications between conventional hosts.

Hardware as a Service

Hardware as a Service (HaaS) simply offers the hardware so that your organization can put whatever they want onto it.

Cloud Computing Security

Security is the number one issue when it comes to cloud computing. Cloud computing provides following advantages when it comes to data security.

Data theft

The biggest security benefit of cloud computing is the centralization of all data. Organizations have an issue with asset protection because data could otherwise be stored in numerous places, like laptops and the desktop.

Outsourcing work

Outsourcing your computing needs to someone who specializes in it could be very good from security standpoint. It’s up to the cloud computing service providers or companies  to provide adequate security. The cloud computing companies would be responsible to maintain latest security features and standards. Security becomes part of the cloud computing companies core competence.


Logging is critical to cloud computing security. Centralized logging can keep tabs on who is performing what tasks. In the virtualized world of cloud computing, providers or companies can maintain or add as much storage as needed to extend logging.


If there is a breach, the cloud computing providers can respond to the incident with less downtime . The virtual machine can be cloned and offline analysis can be done. Further, many individual companies do not have a dedicated in-house incident response team. If there is a problem, IT staff have to quickly figure out their new job of taking the serverdown, quickly investigating, and getting it back online for minimal production downtime.  Centralized cloud computing security can cut down this time drastically.


Centralized cloud computing services require centralized auditing mechanisms. The audit trails are generated and secured easily as all information is at one single place.


The same security issues that your organization deals with are the sorts of issues that SaaS / cloud computing providers face, these inlcude

  1. Network security
  2. Hardware security
  3. Applications security
  4. Data security.

Regulations like Sarbanes-Oxley (SOX), Gramm-Leach-Bliley (GLBA),  HIPAA, and industry standards like the Payment Card Industry Data Security Standard (PCI DSS) make things particularly challenging and are best handled by cloud computing providers specializing in this. Prior to SaaS, compliance could be managed by a few tasks:

  1. Identify users and access privileges
  2. Identify sensitive data
  3. Identify where it’s located
  4. Identify how it is encrypted
  5. Document this for auditors and regulators

It becomes cloud computing providers to enable their customers meet the regulatory standards.

Cloud Computing Companies

So who all are cloud computing companies ? Here are some of the big names:

cloud computing

Amazon cloud computing

Amazon was one of the first companies to offer cloud services to the public. Amazon offers a number of cloud computing services . These services are used via a command line interface. Amazon’s virtual machines are versions of Linux distributions, so those who are experienced with Linux would not have any difficulty. Applications can be written on your own machine and then uploaded to the cloud.

Google cloud computing

Google provides many free cloud computing services. Google cloud computing offers online documents and spreadsheets, and encourages developers to build features for those and other online software, using its Google App Engine.

Microsoft cloud computing

Microsoft cloud computing solution is called Windows Azure, an operating system that allows organizations to run Windows applications and store files and data using Microsoft’s datacenters. It’s also offering its Azure Services Platform, which are services that allow developers to establish user identities, manage workflows, synchronize data, and perform other functions as they build software programs on Microsoft’s online computing platform.