Web 2.0

Web 2.0 is the term given to describe a second generation of the World Wide Web that is focused on the ability for people to collaborate and share information online. Web 2.0 basically refers to the transition from static HTMLWeb pages to a more dynamic Web that is more organized and is based onserving Web applications to users. Other improved functionality of Web 2.0 includes open communication with an emphasis on Web-based communities of users, and more open sharing of information. Over time Web 2.0 has been used more as a marketing term than a computer-science-based term. Blogs, wikis, and Web services are all seen as components of Web 2.0.

Web 2.0 was previously used as a synonym for Semantic Web, but while the two are similar, they do not share precisely the same meaning.

Cloud computing

Cloud computing is a technology that uses the internet and central remote servers to maintain data and applications. Cloud computing allows consumers and businesses to use applications without installation and access their personal files at any computer with internet access. This technology allows for much more efficient computing by centralizing storage, memory, processing and bandwidth.

A simple example of cloud computing is Yahoo email, Gmail, or Hotmail etc. You dont need a software or a server to use them. All a consumer would need is just an internet connection and you can start sending emails. The server and email management software is all on the cloud ( internet) and is totally managed by the cloud service provider Yahoo , Google etc. The consumer gets to use the software alone and enjoy the benefits. The analogy is , 'If you need milk , would you buy a cow ?' All the users or consumers need is to get the benefits of using the software or hardware of the computer like sending emails etc. Just to get this benefit (milk) why should a consumer buy a (cow) software /hardware ?

Cloud computing is broken down into three segments: "application" "storage" and "connectivity." Each segment serves a different purpose and offers different products for businesses and individuals around the world. In June 2011, a study conducted by VersionOne found that 91% of senior IT professionals actually don't know what cloud computing is and two-thirds of senior finance professionals are clear by the concept,^[1] highlighting the young nature of the technology. In Sept 2011, an Aberdeen Group study found that disciplined companies achieved on average an 68% increase in their IT expense because cloud computing and only a 10% reduction in data center power costs.^[2]

Difference b/w SOA and SOAP

SOA ( service-oriented architecture)

There are a lot of definitions of Service Oriented Architecture, some of which are: 

A service Oriented Architecture is a set of components which can be invoked and 

whose interface descriptions can be published and discovered. 

SOA is an architectural style whose goal is to achieve loose coupling among 

interacting software agents. A service is a unit of work done by a service provider to 

achieve desired end results for a service consumer. Both provider and consumer are 

roles played by software agents on behalf of their owners.

Service-oriented architecture (SOA) is an architectural software concept that defines 

the use of services to support business  requirements. In an SOA, resources are 

made available to other participants in the network as independent services that are 

accessed in a standardized way. Most definitions of SOA identify the use of web 

services (using SOAP, WSDL and UDDI) in its implementation; however it is possible 

to implement SOA using any service-based technology. 

SOAP (Simple Object Access Protocol)
One of the most significant characteristic  of Web Services is their loose coupling.

They are not only independent from the infrastructure they are running on. It doesn’t

make any difference (in contrast to Component-based Architecture) if one service

using another doesn’t run on the same computer, or doesn’t use the same

language/operating system. Web Services released with .NET can easily be coupled

with Web Services written in Java, as if both were Java or .NET builds. 

In addition, they can be exposed to the internet so that everyone can use

components he is not the owner of, without taking them away from their owner, or

having to copy them. Web Services are designed to be published as far as possible

like web sites. They should be like web site for machines and computers.