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You are here: Home / API Blog / What is an API: Everything You Need to Know About APIs?

What is an API: Everything You Need to Know About APIs?

September 17, 2019 By Alfrick Opidi Leave a Comment

We’ll cover all you need to know about APIs (Application Programming Interfaces) in this post. Let’s begin by defining what an API is in plain English.

Table of Contents

  • 1 API in Plain English
  • 2 What is an API?
    • 2.1 How do APIs work?
  • 3 Different types of APIs
    • 3.1 APIs by release policies
    • 3.2 APIs by specifications or protocols
  • 4 What About REST & SOAP APIs?
  • 5 Web APIs
    • 5.1 What is a Web API?
  • 6 Examples of APIs
  • 7 Common API terms
  • 8 Using an API
  • 9 What are the benefits of using an API?
  • 10 Conclusion
    • 10.1 Share this:

API in Plain English

The acronym API stands for Application Programming Interface. APIs allow software systems or bits of code to communicate with one another. We communicate with physical interfaces every day. Examples of physical interfaces include a phone’s screen and a computer’s keyboard. Just like you use a screen to interact with your phone, software systems use APIs to interact with each other. Since software is deeply ingrained in our everyday life, it is no exaggeration to say that every aspect of our life depends on APIs.

Let’s take a closer look at APIs now.

What is an API?

APIs (Application Programming Interfaces) are used to connect different software together. It allows a developer to use one piece of software to make calls to another piece of software.

API refers to a set of programming instructions that enables the interaction between software components. Basically, an API service is a collection of specifications that computer systems use to “talk” to each other and share functionalities.

How do APIs work?

API stands for Application Programming Interface, which is a collection of programming instructions that allows software components to communicate with one another. An API service is a set of standards that computer systems utilize to communicate and share functionality.

When you input https://www.wikipedia.org/ into your web browser, for example, your browser connects to the Internet and makes a request to the website’s server. The server then analyses the data and responds to the browser, which analyses the response and displays the relevant information in a human-readable way. This is how an API works: all of these activities are carried out through it.

An Application Programming Interface is essentially the interface that allows the web browser, also known as a client, and the website’s server to connect. As a result, anytime you visit a website on the Internet, you are sending and receiving data to a remote server via an API.

Here’s a diagrammatic illustration of how APIs function, courtesy of Medium:

How APIs work

To further understand what an API is, consider buying meals from a restaurant. If you’re in a restaurant, you select what you want to eat from the provided menu. While the kitchen is the “server” who will cook your food, there is a vital missing link that will convey your order to the kitchen and serve you at your table.

So, a waiter (or an API) comes in and takes your order (or request) and instructs the kitchen (or the server) about what you need. Consequently, the waiter delivers you the meal (or the response).

Just like you’d consume the food without caring about the intricacies of preparing it, users usually consume APIs without really knowing what is taking place behind the scenes.

Different types of APIs

There are several methods for classifying APIs into different types. In this article, we’re going to talk about the following two main methods for classifying APIs:

  • APIs by release policies
  • APIs by specifications or protocols

APIs by release policies

According to release policies, APIs can be categorized into three main types:

  • Open APIs—also called public APIs, implying that they are publicly available and anyone can access them without any restrictions.
  • Partner APIs—these APIs are made available under partnership agreements, implying that you need to be granted a license before accessing them.
  • Internal APIs—also called private APIs, implying that they can only be used within an organization.

APIs by specifications or protocols

The objective of API specifications is to stipulate rules or procedures that standardize the exchange of data between computing infrastructures. In the case of APIs, standardization implies the capability of disparate systems, created using various programming languages or various technologies, to interact with one another flawlessly.

Further, the classification of APIs by specifications can be divided into two main types:

  • Web service APIs
  • Web APIs

What About REST & SOAP APIs?

Essentially, a web service refers to an application or a data source that is available over the Internet and uses an address, such as an URL, to allow access to its services. A web service is characterized by the provision of open standards and protocols that support interoperable communication between diverse software applications.

While there are several types of web service APIs, we’ll talk about two of the most common ones:

  • SOAP (Simple Object Access Protocol)—this is a protocol that supports the structured exchange of data in the XML (extensible markup language) format. So, if you want to know about what is SOAP API, you’ll need to understand how the XML data format works.
  • REST (Representational State Transfer)—it is a set of software architectural principles, and not a protocol, per se. REST is regarded as a simpler alternative to SOAP. REST API refers to APIs that comply with the REST design principles, make their data available as resources, which can be accessed using URLs that point to those resources. Unlike SOAP that supports only a single data format, REST supports a wide range of data formats, including plain text, HTML, XML, JSON, and YAML. Because of its simplicity and ability to support multiple formats, REST is a prevailing choice for creating APIs nowadays. So, if you want to know what is REST API used for, the possibilities are endless.

Web APIs

Essentially, a web API is an open-sourced concept, and not a technology, that can be utilized to create HTTP-based APIs. As the name suggests, it refers to an API available over the web, supports the HTTP protocol, and returns JSON or XML data type by default.

It is important to note that a web API can either be RESTful or not. Programmers can create web APIs using various technologies, such as .NET and Java.

What is a Web API?

Web APIs are a collection of HTTP-based services that make up a public-facing endpoint for applications and services. Web APIs allow companies to rapidly release new products, increase development agility, and reduce third-party application development integration costs.

Difference Between API & Web Service

API is a set of rules that allows two different applications to talk to each other A Web service is a form of networking where two machines can communicate by sending messages back and forth over any network
A network is not a necessary condition for API communication Needs a network, like the Internet, for communication

 

Examples of APIs

With an API, you do not need to reinvent the wheel over and over again. As we’ll mention later in this article, one main benefit of APIs is that they allow you to build applications without having to code them from scratch. And, there are several APIs you can use to create a variety of transformative applications.

In fact, the expansive Rakuten RapidAPI API marketplace has thousands of free APIs to meet any need you want—from listening to music to generating images to getting the latest news, it has all.

Here are two examples of APIs:

    • IP Geo Location API—this free RESTful API allows you to get the geolocation data for any provided IP address. You can use it to display useful comprehensive information about the IP location of your websites visitors, such as data about country location, city location, latitude and longitude coordinates, and time zone. Here is its screenshot:
  • IP Geo Location API Documentation
    • IBMWatsonTTS API—this free RESTful API lets you convert text to natural-sounding audio. With the API, you can create an innovative application that can convert written text into natural-sounding speech in a wide range of languages and tones. Here is its screenshot:

IBMWatsonTTS API Documentation

Common API terms

Here is an explanation of some common terms related to the use of APIs:

    • API key—it refers to a unique identification code that is used to authenticate the user or application wanting to be given API access. An API key helps in controlling and tracking how it is being used, which can avert malicious users or fraudulent activities. Some APIs require unique keys before making a request, while others do not require them.
    • API call – An API call is a request to the API that has been made by a client. The API will then respond with the response data.
    • API endpoint—it refers to the end or touchpoint of the communication interaction between an API and a server. An endpoint can be considered as the URL of a service or a server. Simply, every endpoint is the point of entry where an API can access the resources it requires from a server to accomplish its stipulated tasks. As we’ve seen above, every API works using requests and responses. Whenever an API sends a request to a server, a response is always issued. The place where an API dispatches a request and where the response comes from is what is referred to as an endpoint.
    • API token—it refers to an authentication scheme that uses cryptic strings, time-limited tokens, or other types of tokens to grant a user or an application API access. In token-based authentication, the API usually generates a piece of data that is used to prove the identity of the user or the application.

Using an API

To really get a sense about what is the meaning of an API, let’s demonstrate how you can use an API. And, the easiest way to begin using APIs is to go to the https://english.api.rakuten.net/ platform and search for any remote API you want. In this case, “remote” implies that the resources that the API interacts with are situated separately from the device making the request.

For example, you can use the Deezer API to listen to a music track. To make your first API request using the API, you can click on the GET * Search endpoint, which allows you to search for tracks on the Deezer music streaming platform.

Then, in the parameter field, enter the name of the artist or song you want to search. Lastly, click the Test Endpoint button and you’ll get a response data in a form easy for computers to interpret.

Here is a screenshot showing how to use the Deezer API:

how to use Deezer API

Then, if we looked on the Response Body section, here’s a truncated version of the response data we got:

API response data example

If you look at the above response closely, you’ll notice that, apart from other data, it has a link to the preview music we’ve searched for.

So, to play the track, we simply grab the preview link and post it on a web browser.

https://cdns-preview-9.dzcdn.net/stream/c-9703f30b43625d43eb8fc27b9e90dffb-3.mp3

 

What are the benefits of using an API?

One of the greatest benefits of using APIs is that they make developers’ lives a lot easier. For example, let’s say you want to create an application that displays users’ geolocation details based on their IP address.

Instead of creating your own application from scratch, which could be demanding, you can use an IP geolocation API, such as the above-mentioned IP Geo Location API available on the Rakuten RapidAPI marketplace. With this API, you can provide accurate location data about a user and save yourself the hassle of having to sew your own application together, line of code by line of code.

If APIs were not available, developers would be obligated to do the hard work of creating such complex applications by themselves. However, the API creators have done all this work, allowing you to fetch useful features and integrate them into your environment without many hurdles.

Furthermore, APIs allow developers to leverage the advanced capabilities of technology powerhouses. For example, the above-mentioned IBMWatsonTTS API lets you harness the sophisticated IBM’s machine learning technology to convert text into natural-sounding speech, something which could be difficult to realize with your own resources. What’s more, if there is any improved functionality, the API consumers can take advantage of it automatically and integrate it into their applications.

APIs also save on development costs and time. Programmers can create new applications, add new features to their applications, or complete other tasks simply by relying on the services of third-party providers. As such, developers may not need to deal with the source code or spend time trying to comprehend how the externally sourced solution works. Simply, they fetch their features and incorporate them into applications. In other words, APIs conceal the intricacies and inner details of systems, which greatly boost the productivity of developers.

Conclusion

If you have read this article until this far, then you should have an elaborate understanding of what APIs are and why they are such a big thing in the world of technology.

Consequently, you can read any API documentation and start consuming that API. Importantly, before performing API integration to create a new application or add features to an existing application, you should carry out sufficient API testing.

If you can test and see that it works according to your requirements, then API management will be an easy task. With proper management, the API will assist in taking the capabilities of your application to the next level.

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