Q: What is the importance of virtualization in cloud computing?
Virtualization and Automation are two key concepts on which cloud computing is made. Virtualization is necessary so that virtual machines can be migrated, new virtual machines can be provisioned in a very short time. Also if one virtual machine fails another virtual machine can take over the load. Since cloud computing is related to auto provisioning, transparent scaling etc., virtualization is a key ingredient.

Q: Cloud computing is part of what is talked in WEB 2.0 or is it different. If yes how ?
According to Wikipedia "Web 2.0" refers to a perceived second generation of web development and design, that facilitates communication, secure information sharing, interoperability, and collaboration on the World Wide Web. Cloud computing could at maximum be considered as a driver for Web 2.0 as most collaborative web applications are running on clouds. But they are certainly distinct concepts. While Web 2.0 revolves around social collaborative web applications like Facebook, Youtube etc., clouds are related to the platforms or infrastructure on which such applications can be made.

Q: How can I as an individual user get in to the "cloud" ?
You should use your credit card to signup for various Amazon offerings and take it for a trial spin, you would spend around $20-$40/month if you are just trying things out but read the billing rates and criteria carefully. Google App Engine can be tried out for free. You should signup for the Google app engine and then you can download its SDK and develop applications using the Python runtime or the Java runtime.

Q: Is any web application that can be accessed worldwide through the web termed as application on cloud?
No. Irrespective of where the application is accessible from. It can only be termed as running on a cloud if it runs on virtualized, automatically managed hardware which allows for scaling, failover and dynamic provisioning. Though this infrastructure could be a public cloud like Amazon, Azzure or Google App Engine et al or it could be a private cloud running on your premises.

Q: What is SLA?
Service Level Agreement. Any services offered by a company usually have a service level agreement (SLA) along with it, which assures the customer things like response within 2 hours, 99.999% uptime around the year etc.

Q: Could you mention about something about the Open Source cloud computing software like Eucalyptus?
Eucalyptus is a private Amazon EC2 Clone cloud software which can be used to setup a cloud for yourself. The best way to try it out is to download Ubuntu server edition which comes with Eucalyptus pre packaged.

Q: How is cloud computing different from the domain hosting service providers, who allow to host the website in their servers and allow access to the website over Internet? Is it not the same model as that of Cloud computing?
No. Cloud is also synonymous with dynamic scaling, failover and dynamic provisioning among other things, which differentiate them from the regular data centers.

Q: What about the security of the data, if infrastructure is being used in pay-as-you-go model in Cloud computing model?
Security is a major concern when it comes to cloud applications. Certain regulatory requirements don’t allow customer data to be stored on the cloud or mandate the data to be collocated with the company in the same continent. As cloud computing evolves security standards and practices would evolve removing apprehensions around cloud adoption.

Q: How do we measure performance of my applications that are running in cloud environment and how do we make sure the allotted cloud resources optimally used by my applications?
If you can load test applications by restricting the resources it has in the cloud you could get some indicator of its performance. But performance analysis and memory analysis is usually not possible on the cloud. Though the local sandbox environment could be used for memory profiling.

Q: With "Cloud computing" are we going into a direction where a home user would just need to have an internet connection, with a dumb terminal setup (k/b, mouse, monitor)?
Software as a Service is a part of cloud computing and yes everyone believes that in future users will have dumb terminals and everything else would be on the cloud. But looking at the major outages at Google, Amazon zones and in the optical Internet infrastructure occasionally not everyone is convinced that this vision is achievable or even practical.

Q: What I understand from the Tools and Cloud application (PaaS), is that they can manage the infrastructure - how much CPU utilization to be allocated to your applications, etc. is that correct?
In a private cloud you can control CPU, Memory and Storage. But for example in Amazon you need to get a VM of certain sized RAM, HDD etc. In the Google App Engine such options are not available Google manages everything and you need to authorize Google to charge you. For example 2mm reads, 400TB bandwidth etc.