What is an API in Web Development?

What is an API in Web Development?

API stands for Application Programming Interface. These are tools that allow two software components to communicate with one another. This is based on a set of definitions and protocols. The term “application” when talking about APIs refers to any software with a specific purpose. On the other hand, interface in this context can be seen as a service agreement between two programs.

API enables easy data retrieval and uploading between software systems. By abstracting away more difficult code, API provides you with simpler syntax to utilize. And you can use it to connect to external servers to obtain data for web applications and data that are not static. An example is the weather data from a weather API.

With API, developers can link their applications to multiple systems and produce new software that connects them to other applications. So if it is your first time hearing about an API, view API as an intermediary between you and information somewhere in the cloud or server. 

How Does an API Work?

How do you suppose apps that allow you to sign up and log in with your Twitter, telegram, or Google credentials work? Alternatively, how does your preferred weather app obtain the forecast for today?

Answer: They communicate with other systems to obtain data or confirm your credentials.

We utilize APIs every time we use apps like Facebook or Twitter to send instant messages or check the weather on our phones. This is because they have to connect with another application to generate the responses they give back as outputs. Web APIs allow for the transfer of functionality and machine-readable data between client-server web-based systems. 

For instance, if you create an application and want other programmers to be able to communicate with it, you will need to create an interface. These interfaces include a set of protocols and conventions that other programs can use to communicate with your application. You could even decide to give the app making the requests a fixed number of parameters to ensure that they access the correct data.

The client starts the process by submitting a request to a server, which the server accepts and executes the requested action.

Importantly, a series of endpoints are set up on the server to carry out different operations. Data retrieval from a database, uploading of new data, and data deletion are a few examples of these actions. 

Let’s use some real-life examples to illustrate how an API works.

Example 1

An elevator is a good illustration of an API in the real world. On the surface of an elevator, a series of buttons serves as your user interface. You can get to the floor you want by pressing one of the buttons on the elevator. You are not bothered with how the elevator climbs and descends. All that matters is that the next time the door opens, you are on the right floor according to the button you pushed initially.

Example 2

You cannot simply go to the printing facilities and print yourself a driving license. Instead, you fill out some forms, take a photo, submit the well-filled document to an authorized body, and speak with a representative in some cases. You are completely unaware of what is happening behind the scenes during the time the application is under review. When it is ready, the system notifies you to come to pick up your ID card after comparing your inputs to data from other databases.

Each of the examples above clearly demonstrates how each operation requires you to adhere to a set of parameters or protocols to get results. API employs the abstraction principle (showing functionality by hiding complexity). 

Web development is a significant area where APIs are employed since they increase browser capabilities.

How are APIs Used in Web Development?

A web API can expand browser capabilities, streamline complicated processes, and give web development code an easy syntax. Web APIs let web developers use data from various internet sources to create web pages and web-based apps. One server can communicate with another over the internet using HTTP or Hypertext Transfer Protocol.

Programmers can use a diverse array of APIs while creating a specific website. Some APIs you may be using for Web development are:

  • Web browsers APIs for accessing documents; one such API is the DOM API, which lets you work with HTML and CSS.
  •  APIs for fetching data from a server
  • APIs for manipulating visuals and sketching them, or for making animation loop(WebGL or Canvas)
  • API to retrieve current user position if the user permits, an example is the Geolocation API.
  • Notification API to display desktop notifications to users.

All browsers have a set of built-in Web APIs to support complex operations and to help access data. You can interact with these APIs using one or more JavaScript objects.

For example, You create an e-commerce website with a feature that allows users to find their current location’s latitude and longitude. Once the data is available, it may display the products’ availability as well as their prices and discounts based on where you are.

The Geolocation API, which delivers the coordinates of the browser’s location, is one important API you will be needing for this project. Web applications like search engines, e-commerce sites, maps, and weather apps that depend on a user’s location can benefit from the Geolocation API.

A simple example using Geolocation API:

const posLocator = document.getElementsByClassName("locationSection");

/** create a function to get the user location **/
function getUserLocation() {
  if (navigator.geolocation) {
  } else {
    posLocator.innerHTML = "oopsss!!!! Something seems to be wrong, Geolocation might not be supported by this browser.";

function showUserPosition(userPosition) {
  posLocator.innerHTML = "Latitude: " + position.coords.latitude +
  "<br>Longitude: " + userPosition.coords.longitude;

Note: You must utilize the navigator.geolocation object’s getCurrentPosition() method to determine the user’s current location.

The getCurrentPosition() method examines the positioning hardware (like GPS) to obtain the most recent information and sends an asynchronous request to determine the user’s location.

Fetching Data From a Server

You can utilize either Extensible Markup Language(XML) or Javascript object notation (JSON) as the communication language when interacting with the server. XML resembles HTML, but the developer has to define the tags.

On the other hand, JSON is typically favored over other formats because it integrates well with JavaScript to make API calls, is easier to read, has a smaller file size, and lacks the open and close tags that XML uses. Nearly all programming languages provide JSON parsers, which are quick, compact, and straightforward.

The majority of current APIs utilize JSON, but some older ones might still use XML, so you should be comfortable with both. A standard transmission method needs to be defined for the client and server to comprehend these requests. A common technique is using a representational state, known as the rest API.

REST APIs communicate smoothly between various app modules, components, and other independent software systems. Communication between a client and a server is made possible via rest.

An HTTP protocol is required first, followed by the method. The method describes the type of activity you want to execute. These include GET, POST, PUT, and DELETE.

  • POST: You can use this method to send new data to the server.
  • PUT: You can use this to modify existing information.
  • GET: This is the most used method, and you can use it to retrieve information from an API.
  • DELETE: This method deletes existing information when called

To test an API using the following methods, Postman is an amazing application to get started with.

Importance of APIs in Web development

APIs make applications perform a purpose-built task centered on data sharing using predefined processes. They enable programmers to create fresh programmatic interactions across the many programs that consumers and companies use daily.

  • It facilitates quicker reactions and has dynamic load-carrying capabilities.
  • increased fault tolerance and improved UI
  • increased cohesiveness
  • API helps in integrating new platforms and systems with existing software systems; this offers businesses greater options to expand.
  • Because they eliminate the need for several programming languages, APIs help accelerate internal processes and reduce costs.
  • It offers smooth integration of third-party services across all types of web interfaces and saves arduous hours of coding.
  • The websites include cutting-edge functionality and features.

Note: You won’t be able to build the proper integration if you don’t have a basic understanding of HTML (a markup language), CSS (web page styling), and, of course, JavaScript (building web pages).

How is Javascript Used in APIs?

You can use JavaScript to create web pages and use them in several other non-browser applications.

On the Client-side, JavaScript allows you access to several APIs that have been put on top of the core JavaScript language. This gives you more flexibility when writing JavaScript code.

For example, you can expose data from the browser and the surrounding computer environment using JavaScript for browser APIs built into web browsers and do practical, sophisticated tasks with it.

The same is true of third-party APIs, which are not included by default in browsers and whose code and information must typically be retrieved via the Internet. For instance, the Telegram API enables you to create your own bots for prompt responses even when you are not online.

Although several JavaScript APIs operate slightly differently, they often share comparable features and functionalities. Your code communicates with APIs using one or more JavaScript objects, which act as containers for the data the API uses and the functionality it provides.

You can get started by creating a very simple web app with vanilla JavaScript that will retrieve information from a fake API.

Tools you need include:

  • HTML
  • CSS
  • JavaScript

Start by creating an HTML file in your Visual Studio code:

<!DOCTYPE html>
<html lang="en">
        <script src="script.js"></script>
        <link rel="stylesheet" href="style.css" />
        <meta charset="UTF-8" />
        <meta name="viewport" 
              content="width=device-width, initial-scale=1.0" />
        <title>For illustration purposes </title>
        <div class="d-flex justify-content-center">
            <div class="spinner-border" 
                 role="status" id="ld">
                <span class="sr-only">Processing...</span>
        <h1>List of Employees in Nitrous</h1>
        <table id="tableContents"></table>

Create a JavaScript file to write some JavaScript code to fetch this data.

const myUrl_Api_data= "https://employeedetails.free.beeceptor.com/my/api/path
/**define an async function fetch and store employee's data**/ 

async function fetching_the_api(url) {
    const res_store = await fetch(url);
    /**Storing data in form of JSON**/
    var data = await response.json();

    if (res_store) {
    display_employee_ data(data);

/** Calling that async function**/

/**Function to hide the loader**/
function hideLd() {
    document.getElementById('old).style.display = 'none';

/**Function to define innerHTML for HTML table**/

function display_employee_ data(data) {
    let static_display = 
    // use a for loop to access all rows 
    for (let x of data.list) {
        static_display += `<tr> 
    <td>${x.name} </td>

    // Setting innerHTML variable
    document.getElementById("employees").innerHTML = static_display;

How to Learn APIs?

You can understand the intricacies of the API if you can write simple code in any computer programming language. So the best way to start learning APIs is to start with the basics. This is because working with REST, SOAP, SOAs, JSON, XML, and others requires you to master technical concepts which you will slowly pick up if you start from scratch.

Importantly, start your programming journey with HTML, CSS, and JavaScript. In these sequences, you can easily learn how to design websites, build web/mobile applications, and build back-end logic. 

JavaScript is especially important for developing the interactivity of a webpage. Some of the best ways to learn JavaScript range from books and tutorials to building your own basic projects.

You could start by building a simple, straightforward web application that shows data from an API. A very user-friendly API for beginners is the weather API and Google Maps API.


Integrating API is a practical method for adding unique features to a web application without creating it from scratch. APIs have a variety of roles in the various software levels and are crucial to successful program architecture.

There are countless APIs, and each one offers something different. There are APIs for every major web software, from Facebook and Google to news sites and forums. Learning how to work with APIs is crucial to becoming a full-fledged developer. You could argue that learning how to work with APIs is even more critical than learning another framework or language since APIs are used across all languages.

The sooner you get started, the sooner you will build that app you have been wanting to make or land that lucrative developer job you’ve been after.