What is a web service? It exchanges data from one system to another in seconds!

Are you interested in knowing what a web service is and how it works? Have you ever wondered what makes communication between applications possible?

Just think for a moment about the applications you use every day. do you have them? Now, analyze what your usability and navigation experience is like in those apps and visualize the way you scroll through them. do you find them easy to navigate?

The power of web services makes it easy for you to move from one application to another seamlessly, and better yet, it makes the whole process of data exchange easier for you.

So, if you want to enter the world of web development, we’ll tell you what a web service is and what it’s for. And as all that glitters is not gold, we will also detail the advantages and disadvantages of a web service. In addition, we will explain each of the existing types of web service and how the architecture of a web service works. Finally, we will guide you through the best examples of web service that will serve as inspiration.

Definition of web service

A web service or web service is a software with a text-based format that works with the Internet. This system is responsible for allowing the transmission of requests and responses between different servers or applications, regardless of the differences that exist between the programming languages in which they were developed or the platform on which they run.

In other words, a web service is, as its name suggests, a service that enables machine-to-machine communication and data exchange between applications over an Internet network.

One cannot mention the term “web services” today without immediately evoking references such as Amazon Web Services (AWS) or Google’s web service. These tech giants have taken the trophy in addressing the need for application development. The scale of companies like Amazon and Google is exactly what makes modern web services possible.

Thanks to web services, it is possible to perform a lot of everyday interactions between applications, even without you realizing it.for example, using a web service is necessary when connecting your Facebook account information to a game you just downloaded, as well as to use your Google login information, and even to open a new account in another application without filling out the form.

As you can see, web services are part of your daily life and many more aspects than you think, so imagine, now you wouldn’t be reading this information from your mobile without the magic of web service.

Features of web services

Some of the characteristics that distinguish web services are the following:

They allow interoperability and the use of multiplatforms.

Its format is text-based.

It is an easy to use and easy to access tool.

It provides integrated services.

It is global in scope.

Enables the exchange of SOAP (Simple Object Access Protocol) messages.

Interface described in WSDL (Web Service Description Language).

It is based on the HTTP (Hypertext Transfer Protocol) format.

how does a web service work?

A web service works through the interactions that occur between the components of its architecture.

The architecture of a standardized web service is based on the use of three main components:

The web service provider.

The web service requester.

The service broker.

Process of the operation of a web service

On the technical side, the first thing that happens for the operation of a web service is that the service provider sends a WSDL file with the definition of the web service to the service broker. With this file, the service broker is able to know which functions it will be possible to execute on the server through the web service.

Afterwards, the service requester communicates with the service broker to find out who the provider is. The service requester can then communicate with the service provider to send a SOAP request in the form of an HTTP message to the server.

Once this happens, the web service interprets the content of the request and the service provider validates the requester’s request. Subsequently, the web service sends the necessary response data in XML (extensible Markup Language) format, again using the SOAP and HTTP protocol.

Finally, the XML file, sent by the service provider, is validated once again by the service requester, using an XSD (XML Schema Definition) file to interpret it. The resulting information is sent to the software and is ready to be processed.

As you can see, the process that a web service follows to work is very simple and it is only a service of interaction and communication between different applications through the Internet.

Standards used by a web service to work

Surely you have already noticed that web services use a variety of standards and protocols to work, mainly the following three:


The SOAP protocol (Simple Object Access Protocol) is written in XML and is a format for sending messages used to exchange information between applications. It was specially designed for Internet communication and thanks to this protocol you can access a web service.


WSDL (Web Services Description Language) is an XML-based language of the functional requirements necessary to establish communication with web services. This language is the standard format used to describe web services and how to access them, and was designed by Microsoft and IBM.


UDDI (Universal Description, Discovery and Integration) is an XML standard for describing, publishing and finding web services. It is a directory where companies can register and search for web services. This way, you can check which web services are available.

However, according to the Engineering web page, in addition to the above, some of the standards that a web service uses to function are the following:

Web Services Protocol Stack

XML (Extensible Markup Language)

XML-RPC (XML Remote Procedure Call)

Hypertext Transfer Protocol (HTTP)

File Transfer Protocol (FTP)

Simple Mail Transfer Protocol (SMTP)

WS-Security (Web Service Security)

REST (Representational State Transfer)

GraphQL (alternative architecture to REST)

Structure of a web service

Now that you know what a web service is and what it is used for, we will tell you a little about how the format of this type of file is structured so that you can better understand how it works.

In short, a WSDL file contains the following elements in its format:

Type element: describes the non-standard types used by messages (Message element).

Message element: defines the data contained in the messages passed from one point to another.

PortType element: establishes a collection of operations provided by the service. Each operation has an input message and an output message that corresponds to some previously defined message.

Binding element: describes the web service protocols used to carry out communication on a given PortType.

Port element: defines an address (URL) for a given Binding.

Service element: defines a collection of Ports.

As you can see, the structure of WSDL files is quite simple and easy to understand. On the other hand, the basic structure of WSDL files can be divided into two parts: the service interface and the service implementation. For this reason, we could divide the elements as follows:

Service interface





Service implementation



datos de web serviceSource: Pexels

Types of web service

These are the most commonly used types of web services:


This is the most basic web service protocol for exchanging data between a wide variety of devices on a network. This web service uses HTTP to transfer data quickly and easily, and communicate other information from the client to the server.


It is an XML-based standard for detailing, publishing and discovering web services. Basically, it is an Internet registry for businesses around the world. The goal is to streamline digital transactions and e-commerce between enterprise systems.


It is an XML-based web service protocol for exchanging data and documents over HTTP or SMTP (simple mail transfer protocol). It allows independent processes operating on disparate systems to communicate via XML.

4. RESTful

One of the types of web service that provides communication and connectivity between devices and the Internet for API-based tasks. Most RESTful services use HTTP as the supporting protocol.

Differences between SOAP and RESTful web services

SOAP web services and RESTful web services are among the most widely used by web developers, but what is the difference between the two?

One of the main differences between these types of web service or web services is the protocol or format they use to exchange data between applications, the SOAP protocol or the REST protocol.

So far, web services that work with SOAP are the most common. On the other hand, web services that use the REST protocol work almost the same as those that use the SOAP protocol.

However, RESTful web services have some differences, since, compared to the SOAP protocol, the REST protocol is not structured under defined standards and is lighter. It is also much more flexible and allows it to work not only with XML, but also with JSON (JavaScript Object Notation), among others.

tipos de web serviceSource: Pexels

Advantages and disadvantages of a web service

Probably at this point it will be very easy for you to deduce what are the advantages and disadvantages of a web service. But, in case you still have some doubts, here is a list of them:



Interoperability is a feature of web services that allows any of these to be able to interact with another web service regardless of the language in which it is implemented, so developers do not have to worry about making any changes in their environments to make use of a web service.


The fact that web services communicate through HTTP and XML formats makes them highly flexible and adaptable to different devices capable of working with these technologies. That is why web services are used and implemented in different electronic devices and are increasingly part of our lives.

Low complexity

Due to the way in which a web service is structured and how it works, the complexity of its use is reduced and, therefore, it is also more accessible. There are even tools that make its creation even faster and easier.


The vast majority of software companies support the SOAP protocol, with which most web services work, so it is very convenient to use this system.



Sometimes web services are published without any security restrictions, which can make them unreliable when the data to be exchanged between applications is sensitive.


Although it is possible to carry out transactions through a web service, there are other types of software that are much more developed for such actions than a web service and that specialize in this type of operations.


One of the disadvantages derived from the fact that web services work with a text-based format is that their performance is low in comparison with other distributed computing models, such as Java Remote Method Invocation (RMI), CORBA or Distributed Component Object Model (DCOM). This is because XML’s goals do not include conciseness or processing efficiency.


Despite all its technological advances, web services testing and processing is still a bit slow. Because they rely on operating systems to manage applications, the smallest variations can result in multifaceted workflows when trying to move data between servers and the cloud, which can affect your ecosystem and your application integration strategy.

Web service examples

Given the rise of web services and their great performance, many companies started using them as a software business model. As we mentioned before, most technology giants did not lag behind and immersed themselves in this great tool. let’s take a look at some of the best web service examples!

1. Amazon Web Services

Amazon, one of the most popular e-commerce companies, has a web service interface that offers a number of interesting features. The possibilities range from simple queries of Amazon catalogs to ecommerce websites that operate in partnership with Amazon through its affiliate program.

The mechanism Amazon uses to expand its online business activities is based on cloud-based web services. Using this technology, Amazon Web Services (AWS) provides access to Amazon’s technical infrastructure. Basically, AWS can be deployed using either SOAP or REST types of web services, but most AWS deployments follow the REST approach.

To get started using AWS, you must first set up an AWS developer account. Once registered, you will receive a subscription ID, which will be used as a key to gain access to the free web services offered by Amazon, although some require paid subscriptions or involve pay-as-you-go fees.

Amazon Web ServicesSource: Amazon

2. Google

Google provides a SOAP-based web service interface to its public search engine to access its resources in a web services model. In fact, this web service is called the Google Web API.

The Google API can be used to programmatically access a number of different services, including running a Google search and receiving the results, requesting a spelling suggestion, and fetching a cached page.

In addition, you can use their web service to query the Google search engine from an application instead of a browser, so the search results are recorded as structured data for the requesting application to process the information.

Like Amazon Web Services, to use the Google Web API, you must create a Google account and receive a key that is transmitted with each request.

API web de GoogleSource: Freepik

3. T-Mobile

Sometimes, web services can help enable a new business model. T-Mobile International is one of the world’s leading international mobile communications providers.

One of its service offerings, T-Mobile Online, provides a wireless Web portal for more than three million T-Mobile customers in Austria, the Czech Republic, Germany and the United Kingdom. As with most wireless plans, the business model is based on consumer usage.

T-Mobile realized that to promote consumer usage it needed to provide interesting content on the portal. One of the biggest challenges T-Mobile faced was finding a way to give content providers access to information about individual consumers.

For that reason, sourcing web services was critical to make sure it was as easy as possible for content providers to join the network.

logo de T-Mobile

that’s it! Now you know what a web service is, how it works and everything there is to know about this data exchange technology between applications. We hope you find this information useful when launching your next app.

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