A web service is a remotely accessible method for exchanging data, typically using XML, and serves to reuse business logic over the internet. It operates on a web server, listens for HTTP requests, and expects SOAP messages for remote procedure calls. The document discusses two main approaches for web services—REST and SOAP—and mentions the evolution towards cloud computing and software as a service (SaaS).

2.  A Web Service is a method that is callable remotely
across a Network.
 Web services are a platform independent way to
exchange data using XML.
 Web services are components of business logic that
can be accessed over the Internet.
 Web services are a way of re-using someone else’s
logic without re-creating it yourself.

3. A Web service is an application that:
 Runs on a Web server
 Exposes Web methods to interested callers
 Listens for HTTP requests representing commands to
invoke Web methods
 Executes Web methods and returns the results
 Most Web services expect SOAP messages.
 SOAP is an XML-based vocabulary for performing
remote procedure calls using HTTP and other protocols.
(http://www.w3.org/TR/SOAP).

4. • Content-based Services
serve up Web Pages for
Human Consumption.
• Web Services Serve up
Data for the computer.

5. Two approaches are widely used
•Representation State Transfer (REST): It allows
use of standard HTTP request to a URL to
execute a request and return data.
(Returned data is encoded either in XML, or in
JavaScript Object Notation (JSON))
•Big Web Services: It uses XML representation
for sending request data, as well as for returning
results standard protocol layer built on top of
HTTP.

6.  Microsoft TerraService:
http://terraservice.net/terraservice.asmx
http://winserv1.cs.uakron.edu/xiaotest/CityVi
ew.aspx
 Ubid:
https://www.ubid.com/app/mypage/Login.asp
x
http://login.live.com/login.srf

7. Web Service started to evolve into Cloud Computing,
where the software is in the “cloud”. One of the
main techniques for Cloud Computing is software as
a service (Saas).
 Amazon E-Commerce Service (ECS) / Amazon Web
Services (AWS):
http://aws.amazon.com/ (Cloud Computing)
Discussion Forums:
http://developer.amazonwebservices.com/connect/forumin
dex.jspa
 Google Apps: (Cloud Computing)
http://www.google.com/apps
http://code.google.com/intl/en/
http://www.google.com/apis/maps/
http://maps.google.com/

8. 
There are many ways to write Web services:
 Write Web services by hand;
 Use SOAP toolkits from Microsoft, IBM, and other companies;
 Use the .NET Framework (easy to manage & need to install IIS
and ASP.NET,
http://www.cs.uakron.edu/~xiao/windows/IISUpdateProcedure.ht
ml)

9. Thank You….