Web Services
In the most naive fashion, a web service can be defined as system software that promotes interoperability amongst remote machines over a network such as internet. Some other approaches providing same functionality as web service are OMG, CORBA, Microsoft's DCOM or SUN's Java/ Remote Method Invocation (RMI).The use of a these services comes into play when widgets make a request to a program running on another server (a web service) and use that program's response in a website. Web services can also be exploited for marketing of a business or a product and can be very useful in trade shows where visitors can avail information from these once they are setup over a server to attract potential clients.