Introduction

In the modern digital technology landscape, almost everything is interconnected. Having a seamless exchange of information and resources between applications drives efficiency and robustness. APIs are one of the reasons why we have this connectivity.

So, what exactly are APIs, and why do they play a crucial role in the software industry?

Whether you are a curious novice or a seasoned developer, this article will help you understand what an API is, how it works, and why they are a big deal.

What are APIs:

Before delving into the concept of APIs, it’s important to understand that API is an abbreviation for Application Programming Interface. You’ve likely encountered APIs without realizing it. Here’s a fun fact: your web browser uses APIs to retrieve search results from other applications.

APIs are the interface for software applications to communicate with each other and exchange resources. They generally provide a standardized way for two applications to communicate, enabling your software to interact efficiently.

Think of the times when you shared a post from Instagram to Facebook, booked a flight on Kayak, or processed payment on an e-commerce site like Ali Express. You’re witnessing APIs in action!
They enable these platforms to communicate and display content across different apps, making your user experience seamless and fun. Now, you can understand why APIs are such a big deal; they perform important behind-the-scenes actions on any application.

Why do we need APIs:

Firstly, you can conveniently share your adorable videos from Facebook to Instagram without switching tabs. Imagine having to switch between tabs each time you want to share videos, book a ride, or shop on AliExpress.

Think about how your internet activity without APIs will be.

These are some of the use cases of APIs:

1. Integration: Instead of building a massive do-it-all software, two or more applications can work together to provide services needed for functionality. Eg Shopify integrated Stripe to process payments.

2. Resource sharing: When two software applications communicate through an API, they share resources. The API ensures that only the requested resource is shared without compromising the database of the application that sends the resource (server). For example, Weather apps get real-time data through a third party.

3. Interconnected Services in Applications: APIs play a vital role in connecting various services within applications. This can range from third-party integrations for features like social media sharing to embedding interactive maps or integrating machine learning capabilities, enhancing the overall functionality and user engagement.

How APIs work:

To understand the behind-the-scenes actions of APIs, there are common terms that you must know:

CLIENT: This is the user of the information the API provides. The client places a request for a resource. For instance, your browser is a client because it interacts with the APIs of different websites to get the resource you requested. When a client requests a resource that is not available, the server throws an error.

RESOURCE: This is the information the API can provide. For instance, a Facebook API resource includes images, usernames, etc.

SERVER: This contains the information the client needs. The server responds to the request and gives the information if available, without granting access to its database.

REQUEST: This is the specific action the client wants the server to perform on a resource. It may involve retrieving information or making changes to the resource.

There are four basic request methods: GET, POST, PUT, and DELETE.

• GET: To retrieve a resource.

• POST: To create a new resource.

• PUT: To edit or update an existing resource.

• DELETE: To delete a resource.

RESPONSE: This is the information the server returns in response to the request sent by the client.

A Typical Behind-the-scene Action of an API

1. Request from Client: The client application makes a request to the server to access a particular service, retrieve data, or perform an action. For instance, you want to check the weather, and you open your web browser (let’s say Google Chrome) and navigate to a weather website or application that uses the OpenWeatherMap API.

2. API Endpoint: The client interacts with a specific endpoint provided by the API. An endpoint is a specific URL or URI (Uniform Resource Identifier) that corresponds to a particular functionality or resource. It’s like a digital doorway to the service offered by the API.

   The endpoint for the weather app might look like:

3. https://api.openweathermap.org/data/2.5/weather?q=city_name&appid=your_api_key.

4. HTTP Methods: The client uses HTTP methods (such as GET, POST, PUT, or DELETE) to communicate the type of action it wants to perform on the API. For example, a GET request is often used to retrieve data, while a POST request is used to send data to be processed.

   For your weather application, your browser sends an HTTP GET request to the specified API endpoint, including the city name in the query parameter and an API key for authentication.

5. Server Processing: The API, hosted on a server, receives the client’s request. It processes the request based on the specified endpoint and HTTP method. This may involve querying a database, performing calculations, or executing other operations.

   For your weather application; The OpenWeatherMap API server receives the request, processes it, and fetches the current weather data for the specified city from its database or external sources.

6. Data Format (Serialization): The data is then serialized into a format suitable for transmission. Common formats include JSON (JavaScript Object Notation) or XML (eXtensible Markup Language). Serialization is the process of converting complex data structures into a format that can be easily sent over the Internet.

7. HTTP Response: The API server sends back an HTTP response to the client. This response includes the requested data or indicates the success or failure of the operation.

   For your weather application;

   Your browser receives the response from the API. The weather website is programmed to interpret the JSON data and extract the relevant information that you requested, such as temperature, conditions, and humidity.

8. Client Processing: The client processes the received data or response according to its programming.

For your weather application; The website dynamically updates its interface, displaying the current weather information for the specified city to you as the user.

Real-life Applications of APIs:

APIs make our online experience fun and functional. Google Chrome, Mozilla Firefox, Explorer, and any other browser you can think of cannot work without APIs.

How?
The browsers we use heavily rely on APIs to provide the rich user experience we are accustomed to. The way browsers work is that they request resources from different servers and display the response, which is what we see on the home page of our browsers.

APIs make communication between the browser and other applications happen. The web itself is built on a collection of standardized APIs that enable communication between different software components.

Other real-life applications of APIs are:

1. Social Media Feeds:
   APIs are the lifeblood of social media platforms. When you share a post from Instagram to Facebook or Twitter, you’re witnessing APIs in action. They enable these platforms to communicate and display content across different apps, turning your feed into a lively social hub.

2. Weather Apps:
   Ever wondered how weather apps collect real-time data? Weather apps use APIs to fetch real-time data from meteorological services, ensuring you’re prepared for sunshine or showers wherever you go.

3. Travel Bookings:
   When planning a trip on a platform like Kayak, you can compare prices, book flights, and reserve accommodations seamlessly. Kayak as a platform does not have all this information. Once you search, the site communicates with the APIs to get the resource you requested. These APIs enable these platforms to fetch and display information from airlines, hotels, and more, making your travel plans a breeze.

4. Online Shopping:
   APIs turn online shopping into a smooth experience. When you browse products, APIs fetch details like prices, availability, and reviews from various sources, allowing you to make informed choices without navigating through multiple websites.

Thanks to APIs, we can share those cute videos, have a shopping spree, make vacation plans, stream music, and more, with a rich and seamless experience.

Don’t Miss Out On…

APIs are changing the way we build applications; they are crucial in the modern software industry. APIs are responsible for seamless integration, increased functionalities, and scalability. Because of their importance, the API industry is continuously growing.

If you are venturing into tech, you need a decent knowledge of APIs. Beyond knowing APIs, there are different opportunities in the API industry.

Check out: API documentation, API development, API testing

The vast opportunities in the API industry are limitless, there are amazing things you could do with APIs.

You can get started with APIs here : A Beginners Guide to APIs: A Practical Step