What is an API?

What is an API?

API stands for Application Programming Interface. It is a set of rules and protocols that allows two software applications or systems to communicate and interact. APIs define how requests and responses should be structured so that different software components can work together seamlessly.

In simpler terms, an API acts as a bridge that enables one application to access the functionality or data of another without exposing its internal workings.

Think of it as a waiter in a restaurant:

• You (the customer) tell the waiter your order.
• The waiter takes your order to the kitchen.
• The kitchen prepares the food and gives it to the waiter.
• The waiter brings the food back to you.

Here, the waiter is like the API facilitating communication between you (the user) and the kitchen (the system).

💡 In simple terms, APIs are tools that allow two software programs to talk to each other by following specific rules and guidelines.

Illustration

For now, think of API as a black box that takes input from the user and generates output.

In the upcoming lessons, we will explore the concept of the black box in greater detail. We will examine how APIs are constructed and discuss the different types of APIs.

Real-world use cases

Here are real-world examples of APIs using popular companies like Uber, Google Maps, Stripe, and Amazon:

Uber API

Scenario: Ride-Hailing and Integration with Other Apps

• When you use Uber, the app connects drivers and riders. Uber’s API enables other apps to integrate its services.
• Example:
  • A travel app like Expedia can use Uber’s API to let users book a ride to the airport directly from their app.
  • The app sends a request to Uber’s API, retrieves available rides, and allows you to book one without opening the Uber app.

How It Works:

• The travel app asks Uber's API for ride options.
• Uber API sends back the ride details (car type, ETA, cost).
• The app allows you to confirm and book the ride.

Google Maps API

Scenario: Location and Navigation Services

• Many apps and websites use Google Maps API to show maps, routes, or location-based data.
• Example:
  • A food delivery app like Zomato or DoorDash uses Google Maps API to show the restaurant's location and the route the delivery driver takes.

How It Works:

• The app sends a request to Google Maps API with the restaurant and customer’s addresses.
• The API responds with the map, estimated delivery time, and directions.
• The app displays this information to the user.

Stripe API

Scenario: Payment Processing

• Stripe provides APIs for secure online payments. E-commerce websites use Stripe API to handle transactions.
• Example:
  • A small business selling products online uses Stripe’s API to let customers pay with credit cards.

How It Works:

• The website sends the customer’s payment information (card number, amount) to Stripe’s API.
• Stripe processes the payment with the bank and sends back a response (success or failure).
• The website shows a confirmation message if the payment is successful.

Amazon API

Scenario: Product Search and E-commerce Integration

• Amazon provides APIs that allow businesses to sell Amazon products on their websites or apps.
• Example:
  • A price comparison website uses Amazon’s Product Advertising API to show Amazon’s products alongside competitors' prices.

How It Works:

• The website sends a request to Amazon’s API for product details (e.g., "laptops under $1,000").
• Amazon’s API returns product names, images, prices, and links to buy.
• The website displays this data, making it easier for users to compare prices and make purchases.

These examples show how APIs act as invisible bridges, enabling seamless interactions across platforms and making life easier for businesses and users alike.