At this very moment, APIs (application programming interfaces) are connecting our digital world in ways we never thought possible. At work, we’re able to complete projects faster and more effectively with real-time analytics and highly integrated tools. And in health care, APIs are bringing together crowdsourced clinical data and research teams, vastly accelerating new treatments and allowing providers to improve quality of care by leaps and bounds.

You might be wondering: How does the small but mighty API make such an impact? Let’s review the basics of APIs and how they integrate applications.

What is an application programming interface (API)?

An API is the interface that allows two independent software components to exchange information. An API acts as an intermediary between internal software functions and external ones, creating an exchange of information so seamless that it often goes unnoticed by the end user.

What is the function of an API?

A simple API. Source: Experian

Put simply, an API functions like a virtual middleman, relaying information from one interface, like a mobile app, to another. APIs connect different parts of a software platform to ensure that information ends up in the right place.

These connection points function not only as an internal communications channel but also as a means for external tools to access the same information. As such, APIs can fall into one of two categories:

  • Internal/private APIs
  • External/open APIs

Private APIs

A private API is only accessible to developers and users within an organization. These APIs typically connect internal team processes to reduce siloed work and streamline collaboration.

Open APIs

Open APIs, on the other hand, provide external developers with a way to easily access and integrate information from one tool to another. An open or public API saves developers time by allowing them to connect their platform with previously existing tools, reducing the need to create entirely new functions.

API examples

In practice, an API can be used to connect virtually any processes. Here are a few common examples of APIs:

  • Sharing flight information between airlines and travel sites
  • Using Google Maps in a rideshare app
  • Building chatbots in a messaging service
  • Embedding YouTube videos into a webpage
  • Automating workflows between B2B software tools

To search, collect, and share data

Discount travel sites like Kayak use APIs to aggregate real-time information from airlines, hotels, and excursions. Without a streamlined way of accessing this information, Kayak would either need to manually collect this data or cease to offer competitive travel deals altogether.

Other examples of APIs that share real-time information include The New York Times, which allows you to analyze their database of thousands of articles, and Spotify, which enables you to search for different types of music. Even NASA has an open API chock-full of satellite imagery and constellation data for public use.

To reduce redundant work

With such a wide variety of products and services available all over the world, it’s not hard for developers to find themselves creating something that’s already been made. APIs can provide teams with premade tools and features that save them from creating these tools from scratch.

For example, YouTube’s API enables developers to embed video players into their site, reproduce reports, and access other helpful resources.  

To empower innovation and collaboration

In a few cases, APIs have been at the forefront of innovation in technology and the sciences. Take, for example, research in genomics: Without global collaboration and quick access to data, research remained siloed and progress was slow. Now, APIs like Google Genomics allow researchers to easily analyze vast quantities of genetic research, helping them discover new treatments and learn more about how genetic conditions develop.


With so many different applications out there, you might be wondering: How are APIs standardized? While the world hasn’t settled on a universal standard, there are a few leading contenders.

These standards, called web service protocols, are sets of practices that dictate how data is communicated and how APIs are accessed. The two most popular protocols, REST and SOAP, dominate the competition, with the vast majority of open APIs using one of the two.

  • SOAP, which stands for Simple Object Access Protocol, was the hands-down favorite for API developers until recently. Now 70% of public APIs follow REST protocols. That said, SOAP is still used in many major tech companies, offering support for legacy systems that may be compatible only with it.
  • REST, which stands for Representational State Transfer, is the newcomer to web service protocols and allows for a greater number of data formats. Additionally, REST tends to be easier for developers to access while offering faster load times and better performance.

Get connected with API resources

Ready to start leveraging the power of APIs in your organization? Check out these resources on getting started. And while you’re at it, learn how Wrike’s API can transform the way you work.