What is a Web Service?

A web service is a set of protocols and standards that are used to exchange data between applications. Different software applications developed in different programming languages, and executed on any platform, can use web services to exchange data on computer networks such as the internet.

In a clearer way it could be said that a web service is a function that different services or equipment use; that is, only parameters are sent to the server (where the web service is hosted) and it will respond to the request.

 • Characteristics.

1. Interoperability: Web Services can be consumed by clients from another platform.

2. External access from the Internet: they perform a good management for the accesses that come from internet clients.

3. Types of data of the interfaces: the types of data defined for web services corresponds to the data types defined by the majority of programming languages.

4. Use of Internet standards: they use these and thus avoid, as far as possible, reinventing solutions to problems that are already solved.

Why did this need arise?

The Web Services originated to solve three major problems at that time and were:

1. Interoperability

2. Cross firewalls

3. Complexity

In the first computers ran a single program at a time, but to the extent that in the same computer could run several programs at the same time, there was a need to have communication mechanism between them, this was called Task to Task communication and, This mechanism has evolved because computers make up networks. Therefore, this communication must be able to be made between an X program, which runs on the Alpha computer, and another Y program, which runs on the Beta computer.

For this communication to work, there must first be a means of communication between the Alpha computer and the Beta computer; this is solved today with the Internet. And second, program X must know how to converse with program X. For this to happen, the programmer in charge of X must know about Y. In turn, the programmer in charge of Y must know about X, at least in those who refers to the exchange of data. This means that, if there is no agreement between the X programmer and the Y programmer, there is no possible communication.

The magic of Web Services is that the X programmer can create a Web Service to transfer data without having to know the Y programmer, nor the programs that he has in charge. So whoever wants to receive the data only needs to use the Web Service and point. This means that there may be data transfers between different applications -programs- that work on several computers, with different operating systems, and that belong to different companies or institutions.

As an example, if you have sent a material via Federal Express and want to know the status of your office, this company offers you a Web Service.