The Difference Between APIs and Web Services

Differences between APIs and Web Services

APIs and web services are two technical terms that get coalesced to have the same meaning time and time again, and a lot of people tend to use them interchangeably. While some of their features overlap, they have different concepts altogether. Let’s take a look at the differences between APIs and web services.

What are web services?

Web services are a component of a web application. Web services are a collection of rules and technologies that permit two or more components on the web or the internet to interact with each other. These components can range anything from a web server to a web browser. The World Wide Web Consortium (W3C) defines web services as renderers of a standard way of communication between software applications that run on different platforms or frameworks. It’s a system that has been created specifically to support interoperable interactions between machines over a network. A network is always required for the operations of a web service.

WSDL (Web Services Description Language) is the first web service used. It is a set of rules written in XML used to describe web services. Other than that, web services use SOAP (Simple Object Access Protocol) — a messaging protocol that shares XML data through HTTP (HyperText Transfer Protocol) requests.

Basically, a web service just acts as a bridge. It is a connection technology to help components interoperate. These programs all perform specific tasks that other programs need to — including featuring a database, computations and executing scripts. HTTP requests are usually used to send data requests back and forth. These requests then return textual data in JSON or XML format.

What are APIs?

API stands for Application Programming Interface. APIs are usually collections of object classes, routines, protocols and data structures that are offered by operating systems or libraries in order to support application development. It’s a way for standardized communication for two otherwise distanced entities. An API basically receives requests and informs the system what the user wants to do, and subsequently returns the response.

APIs can be easily explained with the example of a restaurant search website. A third-party restaurant search app would require aggregate information from various databases around the internet to deliver you the results that you are looking for. When your query is presented, the app will interact with API to get information from different systems over the internet. It checks for availability, pricing, distance & reviews, aggregates the data and delivers it back on the third-party app.

API is another way of communicating with a software component. Then, what is it that makes APIs separate from web services?

The Key Differences Between APIs and Web Services

1. Web services are a way to communicate between two distant servers over the internet, while APIs are used to do the same between two different applications.
2. Web services are limited by protocols and design patterns, mainly relying on SOAP, and sometimes REST, XML-RPC or UDDI. On the other hand, APIs can use any protocols or design patterns.
3. A network connection is an absolute requirement for web services to function, whereas APIs can be used offline.
4. A lot of public APIs have open documentation and self-service for rapid developer onboarding. Web services instead offer data and functionality to certain patterns only.
5. All web services are considered APIs but not all APIs are web services, owing to the fact that APIs have higher functionality and flexibility in their operations.
6. Web services do not have a lightweight architecture, because they use the SOAP protocol to transfer data over the network. Since most APIs use libraries and data that run on the .NET framework, they have a lightweight architecture.
7. APIs have efficiency, wide reach, personalization, data ownership, time-effectiveness, programming language independence, and easy integration with GUI; Web Services offer loose coupling, synchronous and asynchronous functionality, document exchange support while supporting remote procedure calls.
8. Web services have HTTP exclusive support, while APIs can support HTTP(S), URL requests, Response Headers and so on.

Now you know that API is an interface that enables the communication between two different applications that use different data and functionality, while web services are based on network and fulfill certain specific tasks. Both of them might have different uses, but they’re important and useful.

For more information on APIs and web services or assistance in developing your own web-based or mobile app, contact our experts at Techrev.