API vs. Web Service: Which Differences?

Web API vs. Web Service is a duel to understand, as they both are critical components of modern software architecture. A good developer knows although there is some overlap when using these two terms, they are not interchangeable.

In this article, we’ll explain the differences between a web service and an API, as they serve different purposes depending on the needs of your software. But first, let’s dive into their definitions and characteristics.

What is API?

In a previous article, we discussed the concept and utility of APIs. An API, or Application Programming Interface, is a set of rules and protocols that allow different types of software to communicate with one another. It serves as a link between software systems, allowing them to exchange data and perform specific tasks. The API is a messenger, transporting data from one location to another. APIs are literally everywhere, and they come in all shapes and sizes.

Features and Advantages of APIs

Key API characteristics include efficiency and time effectiveness, customization, simple GUI integration, extended reach, and data ownership.

There are multiple advantages when using APIs. First, APIs are convenient for developers since they require just a few lines of code to be added to their client apps. This is what ZEGOCLOUD solutions enable with their broad APIs offer.

API’s adaptability and scalability are essential to accommodate various client requirements and business projects. That’s why businesses considering implementing Web APIs ensure that API performance does not degrade with scale. They do so with methods like load-balancing and caching.

Control over a single Web API is easy. However, an API management framework is often designed to achieve control over APIs. This way, when companies use many APIs, the Web APIs designer can manage them together.

Tracking services and signaling unusual activities is another advantage of Web APIs. Protection from online assaults and security is, therefore, fundamental.

Further technical advantages that a API are:

Strengthened connection
Supporting the standard create, read, update, and delete (CRUD) operations and utilizing the HTTP PUT, POST, DELETE, and GET verbs
Making service information available to browsers through HTTP, which you may configure and make RESTful.

Disadvantages of APIs

Nothing comes without drawbacks. So do APIs. The most relevant ones are:

The time-consuming process of APIs creation requires talented resources.
Programming knowledge is a must which leads to high costs of APIs maintenance.
Boundary definition and delineation are vague and imprecise
The necessity of a fixed scale
Crashing can occur when testing Web APIs

In essence, APIs are online resources that developers and businesses could build up to offer more digital services to their clients. However, given the disadvantages, internal standards for integrating or coordinating applications might be preferable. Many prefer using APIs that aren’t always dependent on the HTTP protocol, thus, adopting more custom-built solutions.

What are Web Services?

Web services constitute a set of open-source protocols and standards accessible over the Internet. They exchange data between systems or applications, mainly for REST, SOAP – the two most common forms of Web services – and XML-RPC communication. Web services only support the HTTP protocol. Their usefulness is providing features other apps may use among the most popular payment processing, logins, and database storage. To perform complicated processes, Web services can be joined in a loosely connected manner. Programs offering basic services can communicate with one another to deliver more complex services with added value.

Features and Advantages of Web Services

Web services were developed to be used as requests for Web pages that help with data retrieval. Interoperability is the primary goal for developers, and Web services give different applications a way to link their data for this purpose. They serve as construction materials that make it simple to reuse web service components in various services.

Also, with Web services, a developer can integrate several functionalities into a product without coding them all from scratch. Using separate Web services, in fact, allows programs to interact together. Consequently, this leads to much time, resources, and energy saved.

The main features characterizing Web services are:

High interoperability and extensibility
Machine-processable descriptions made possible by the use of XML
Autonomy so that every service exists separately from all other services
Simple to use and agile
In-loose coupling
Support for remote procedure calls and sharing documents. Hence, quicker internal and external communications within businesses

Disadvantages

Web services are excellent at solving some challenges but sometimes introduce new ones. Issues may arise due to the technological underpinnings of Web services or the specifications.

As we learned, Web services support only HTTP protocol. This latter is unreliable since it does not guarantee delivery or response time. Recent versions of the standard Web services allow protocols such as JMS to overcome this problem, but most services still use HTTP, which does not. Therefore, there is execution uncertainty. Consequently, the availability of Web services is a pain point, given the nature of their Internet infrastructure. Just like websites, they might be unavailable sometimes.

When there is a need for responses arising from client-customized machine needs, Web services are not helpful. Matching requirements might be challenging given their technology’s “one-size-fits-all” character.

So, to summarise the most widespread disadvantages of Web services:

Emerging and advanced web technologies like Semantic Web and AJAX XML can not be used.
The response is not guaranteed when submitting a request since HTTP is not very secure.
Available through a network, making these services not useful for local communication.
Inaccessibility through a browser may signal a broken Web service
Specialization is a must when serving various clients, which can be time and resources consuming

Web API vs. Web Service

APIs and web services can ease data transfers between programs through the internet. However, they are different and should not be utilized interchangeably in all cases. Now that we have seen the two technologies’ general characteristics, let us tackle comparing API vs. Web service.

The primary distinction to bear is straightforward: all Web services are APIs, but not all are Web services. More precisely, Web services are a subset of APIs. As we mentioned when introducing the concept of APIs, this is a broad category, including any software component that serves as a bridge between two otherwise disparate applications. Consequently, a Web service is just a method of implementing an API.

More precisely, Web services are APIs accessible only via a network. APIs are application interfaces that do not need a network, allowing communication in any standardized manner.

In the following table, you can find the main differences between API vs. Web service.

WEB SERVICE	API
For communication, it employs three styles: REST, SOAP, and XML-RPC.	It may be used to communicate in any way.
Only compatible with the HTTP protocol.	It supports the HTTP/s protocol, including URL Request/Response Headers.
Generally uses XML to exchange data.	Generally uses JSON to exchange data. It can still be used by a client who understands XML.
Does not come with a lightweight design, making it complex to employ for simple use cases. It requires SOAP protocol to send or receive data over the network.	Provides lightweight architecture that makes it easier to implement.
It requires the Internet to connect two or more software programs to different computers.	Does not necessitate the use of a network. For example, two programs on the same computer may still integrate via APIs.
Only accessible to approved partners. These online service owners have more control over data, performance, and who uses it.	It allows developers to experiment with them without control, while some are only available to paid clients.

Conclusion

APIs and web services allow data to be sent across different software applications. APIs may be thought of as including but not limited to web services. Lightweight architecture makes APIs more widely available. They are an interface that exposes an application’s data to third-party software, and a Web service is one sort of API with stricter criteria. Among these criteria are the following:

network connectivity
SOAP, as the principal protocol,
limited public accessibility.

While these definitions may appear somewhat complicated, understanding the slight but fundamental distinctions across web technologies is critical. Although there are subtle distinctions between these two notions, distinguishing them is crucial to better-comprehending product integrations.