What are web services and how to use them

Web service or website

Let’s start with terms. A web service is an Internet program that provides services or responds to users’ requests. For example, e-mail sends letters, Google searches information on the Internet, and a weather site shows the forecast. Web service is an application in the World Wide Web.

Website is a web application too but it has different functions. This is a page or pages on the Internet that contains some information. Businesses use both kinds of web applications. For example, if you have a travel agency, then a website and a web service will be suitable for your business. That’s how you can select from among them:

• • If you are going to display information about the company, contacts, working hours, work directions, and discounts, then a website will suffice;
  • If users not only get information but also select a tour, a hotel, or create an account, then you should choose a web service.

The functionality of web services depends on its architecture. How is it built and is it important for web services to work?

Find the essence: architecture and protocols

Architecture is a set of components of a web application and a way of interaction between them. The components of a web application are:

• • user’s interface
  • application programming interface (API)
  • databases
  • external services — help web services implement business logic; for example, messaging broker or acquiring
  • cache

The set of components can be different. The main architecture goal is to make the digital product work in a certain business logic tailored to the client application specifications.

Architecture and its components

In fact, we can divide architecture into 2 parts:

• • Client application architecture (frontend) — what a user sees on the screen
  • Server architecture (backend) — what is behind the screen, i.e., a programmed response to the user actions

If you want to imagine a client application architecture, think about building architecture. You see the facade of the house: a number of floors, the windows’ shape, the roof, steps, and the door. It’s the client application architecture, frontend. And then, you go inside and see all the rooms, their arrangement, whether you can go from one room to another. Where the stairs are and where they lead to. At the same time, you notice that there should be a door to get to another part of the house, and here, it would be better to add the stairs to get to the attic, bypassing two floors. It’s a server architecture, backend. And if the building is badly designed, it can even collapse.

That’s how web services are built, but the difference is that the users can’t see the backend

Protocols and technologies

A protocol is a set of rules and methods of interacting between web services components and also between different web services. Usually, web services are based on certain standards. Standards are the rules and regulations that provide a coherent interaction between web services. The standards and sets of open protocols for information exchange include:

• • HTTP, HTTPS, FTP, TCP/IP — network protocols and transmission processing protocols
  • SSL, TLS — an encryption protocol for safe data transmission and retention
  • API — a kit or a description of different methods of how one program can request another
  • XML and JSON — organize the information for exchange
  • WSDL (Web Services Description Language) — is a programming language for web services description; this programming language helps a client service understand how to use the web service
  • SOAP — is a Simple Object Access Protocol; it works with the help of HTTP and allows applications to interact on its basis

How does a web service work on the example of a banking app

Actually, if you’re not a web developer and aren’t going to maintain the web development process all by yourself, then it’s not necessary to know all the protocols and components of a web application. The main point is to understand how a web service works. This way, you will have an easier time assigning tasks to devs and checking up on their work. Let’s figure out how web services work. For example, a client applies for a credit card reissuing via the Internet. The bank needs to unload its operators who create and process requests. For these reasons, banking web service development was launched.

1. The user enters the bank’s Internet site and goes to the request page. They fill it out and click the ‘Send’ button. The request goes to the backend.

2. The backend processes the request and determines whether it’s filled out correctly. If not, then the web service answers the client that an error occurred. If everything is correct, the backend sends the request to the request management service and waits for an answer.

3. A request management service accepts or rejects the request. Then, it sends the message back to the web service. If the request is rejected, the web service informs the client of the error. If the request is accepted, the web service transfers all the data to the message broker.

4. In the message broker, the request awaits distribution between managers. After this, clients get a message that their requests are accepted, and the manager will contact them.

The client doesn’t see steps 2-4 because they occur on the backend side. They only see the result — the request is accepted, or an error occurs.

If you want some more examples of web services, we can tell you how we developed a video content marketplace in 3 months at the link below. In this case, we described the implementation of a web service, what nuances we discussed with a client, what difficulties we encountered, and how we solved them.

Why do we need web services?

There are business spheres where web services can be useful for some companies: the fitness industry, restaurant sphere and food delivery, tourism, and medicine. We can divide the value of web services for business into two groups:

• • Internal value. By using web services, the business process can be automated and simplified. For example, it helps create a report, establish the information exchange between departments, or monitor the goods stock.
  • External value. The interaction with users. For example, by using web services, users can make an appointment online or order goods or services.

The functionality of an Internet web service and its application is limited only by your imagination. However, the startup’s success often depends on how the web service is made and what its features are.

Do you have web service ideas? Write to us, and we will help you make them real. The Purrweb team develops web applications from scratch: we help analyze the market, work through business logic and UI/UX design, create a digital product, and maintain the work of a web service.