What is an API (Application Programming Interface)?
Many people ask themselves, “What is an API?” API is the acronym for application programming interface — a software intermediary that allows two applications to talk to each other. APIs are an accessible way to extract and share data within and across organizations.
APIs are all around us. Every time you use a rideshare app, send a mobile payment, or change the thermostat temperature from your phone, you’re using an API.
When you use one of the above apps, they connect to the Internet and send data to a server. The server then retrieves that data, interprets it, performs the necessary actions, and sends it back to your phone. The application then interprets that data and presents you with the information you wanted in a readable way. What are the characteristics of an API?
The term “API” has been generically used to describe connectivity interfaces to an application. However, over the years, the modern API has taken on some unique characteristics that have truly transformed the technology space. First, modern APIs adhere to specific standards (typically HTTP and REST), which enable APIs to be developer-friendly, self-described, easily accessible, and understood broadly.
Additionally, today, APIs are treated more like products than code. They are designed for consumption for specific audiences (e.g. mobile developers), and they are documented and versioned in a way that enables users to have clear expectations of their maintenance and lifecycle.
Because APIs are more standardized, they can be monitored and managed for both performance and scale. And, most importantly, they have a much stronger discipline for security and governance. The way this works in practice is that – going back to the weather phone application example – your phone’s data is never fully exposed to the server and.
Likewise, the server is never fully exposed to your phone. Instead, each communicates with small packets of data –– sharing only that which is absolutely necessary. We can think of the above concept similar to ordering takeout at your favorite restaurant. You, the customer, tell the waiter what you would like to eat and they’ll tell you what they need in return and, in the end, you get your meal!
And, finally, just like any other piece of software that is productized, the modern API has its own software development lifecycle (SDLC) –– from mocking, designing, and testing to building, managing, and retiring. These APIs are well documented for both consumption and versioning in the process.
Today, APIs have become so valuable that they comprise a large part of many business’ revenue. For example, on average, 35% of organizations’ revenue is now generated by APIs and related implementations. These companies are contributing to a marketplace of thousands of APIs, otherwise referred to as the API economy.
How do APIs work?
Imagine a waiter in a restaurant. You, the customer, are sitting at the table with a menu of choices to order from, and the kitchen is the provider who will fulfill your order.
You need a link to communicate your order to the kitchen and then to deliver your food back to your table. It can’t be the chef because they’re cooking in the kitchen. You need something to connect the customer who’s ordering food and the chef who prepares it. That’s where the waiter — or the API — enters the picture.
The waiter takes your order, delivers it to the kitchen, telling the kitchen what to do. It then delivers the response, in this case, the food, back to you. Moreover, if the API is designed correctly, hopefully, your order won’t crash!
Examples of APIs
How are APIs used in the real world? Here’s a very common scenario of the API economy at work: booking a flight.
When you search for flights online, you have a menu of options to choose from. You choose a departure city and date, a return city and date, cabin class, and other variables like your meal, your seat, or baggage requests.
To book your flight, you need to interact with the airline’s website to access the airline’s database to see if any seats are available on those dates, and what the cost might be based on the date, flight time, route popularity, etc.
The API is the interface that, like your helpful waiter, runs and delivers the data from the application you’re using to the airline’s systems over the Internet. It also then takes the airline’s response to your request and delivers right back to the travel application you’re using. Moreover, through each step of the process, it facilitates the interaction between the application and the airline’s systems – from seat selection to payment and booking.
APIs do the same for all interactions between applications, data, and devices. They allow the transmission of data from system to system, creating a connected experience. APIs provide a standard way of accessing any application data, or device, whether it’s accessing cloud applications like Salesforce, or shopping from your mobile phone.
Types of APIs
There are a few different types of APIs to get familiar with. For example, you may have heard of Java APIs or interfaces within classes that let objects talk to each other in the Java programming language. Along with program-centric APIs, there are also Web APIs such as the Simple Object Access Protocol (SOAP), Remote Procedure Call (RPC), and perhaps the most popular—at least in name— Representational State Transfer (REST) or RESTful APIs. And new API technologies and styles continue to pop up today, like GraphQL and AsyncAPI to name a few. There are over 15,000 publicly available APIs, according to Programmable Web, plus many thousands of private APIs that companies use to expand their internal and external capabilities.
How APIs enable digital transformation
Companies are digitally transforming faster than ever to keep up with their competitors and increase customer demands. APIs help them digitize, connect, and innovate across their products and services. APIs are a key enabler of these efforts. In fact, 90% of executives say that APIs are mission-critical to their businesses. By adopting API-driven strategies, they can drive growth and innovation. Incorporating APIs into business operations can help:
- Simplify and accelerate their go-to-market strategies
- Enhance customer experiences
- Improve operational agility and speed
- Develop and pursue new revenue, market, and channel opportunities
To learn how to establish an API strategy that can enhance the customer experience or transform your business, read this whitepaper on API strategy essentials.