What is Application Programming Interface (API)?

Web Development Jargons Explained in 4 Different Ways

TLDR: Application Programming Interface (API) is an interface that programmers can use to interact with a software system. For example, Bob is a waiter at a restaurant. He relays your order to the kitchen, and Bob brings the food back to you. The kitchen is the software system, and Bob is the API.


Explain like I'm a newbie

Application Programming Interface (API) is an interface that programmers can use to interact with a software system. For example, Bob is a waiter at a restaurant. He relays your order to the kitchen, and Bob brings the food back to you. The kitchen is the software system, and Bob is the API.

The API is in charge of handling requests, checking with the system whether the requests are attainable, and sending back a response. In the restaurant, if the dish you ordered is sold out, the waiter will inform you and ask you to choose another dish.

An API doesn't expose the inner workings of a software system, just like a waiter doesn't tell you about the chaos that goes on in the kitchen.

In web development, an API is usually about creating, retrieving, modifying, and deleting information in a database. The famous Twitter API allows users with programming skills to read their feed, post a new tweet, follow a user, etc., all without using the Twitter App or Twitter website.

Programmers can even use the Twitter API to build custom websites and mobile apps that work just like Twitter. API is the interface created by programmers, for programmers, to interact with a software system.

Explain like I'm a total nerd

API is a general term for a programmatic interface programmers use to interact with a software system. DIY electronics such as Arduino and RaspberryPi, computer operating systems such as Windows and Linux, web services such as Twitter and Facebook, and software libraries will often have an API.

Programmers can use these APIs to interact with the systems, or create new applications out of them.

In web development, APIs mostly conform to the REST (Representational State Transfer) architecture. RESTful APIs have a standard way for retrieving, creating, modifying, and deleting information. These operations are called GET, POST, PUT, DELETE. This standard allows programmers to expect consistency across web service APIs.

Explain like I like videos

Explain like I already know it

Did you know Facebook built an alternative API architecture called the GraphQL? It allows the client to modify the scope and boundaries of the request on the fly. So there is no need to have endpoints that cover all needs. Prevents unnecessary large datasets being returned.

We are trusted by

Students and instructors from world-class organizations

Imperial College London
Carnegie Mellon University
City University of Hong Kong
Hack Reactor
Cisco Meraki
University of Oxford
Swift
Bazaarvoice
Waterloo
Uber
AtlanTech
Tumblr
Boston College
Bombardier Aerospace
University of St. Andrews
New York University
Minerva Schools at KGI
Merrill Lynch
Riot Games
JP Morgan
Morgan Stanley
Advanced Placement®
Google
KPMG
The University of Hong Kong
University of Toronto
SCMP
Moat
Zynga
Hello Toby
Deloitte
Goldman Sachs
Yahoo
HSBC
General Assembly
Tesla
McGill University
Microsoft

Join the upcoming Cohort #72

Enroll for December 5th, 2022