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What Is An API?

An API, or Application Programming Interface, at its most fundamental level, is how software applications to talk to each other using the Internet. An API allows you to open up data and other digital resources, to public developers, businesses, or even between departments and locations within a company. APIs are increasingly the way in which companies exchange data, services and complex resources, both internally, externally with partners, and openly with the public.

What Are APIs Used For?

APIs enable software, or even hardware to to communicate over the Internet, in a secure way. The World Wide Web, uses the Internet, to allow humans to communicate, and share information. APIs, use the Internet to allow websites, web applications, mobile applications, and devices to communicate, and share information.

  • APIs Deliver Functionality to Websites
  • APIs Are Behind Web Applications
  • APIs Power Mobile Applications
  • APIs Connecting Physical Devices

APIs are part of every aspect of our increasingly digital lives. APIs provide the connectivity everyone needs from the cell phone in your pocket, to all the tools you use at the office, and in our home security, appliances, and entertainment.

Who Uses APIs?

APIs may sound like something that is only for geeks, but APIs are making data and resources available to any adventurous individuals—no programming experience required. APIs are being employed by non-technical folks to get the content, data, and other digital resources they need to build applications, visualizations, and the analysis they need to solve real world problems.

When it comes to APIs, there are two dimensions:

  • API Providers - You are designing, deploying, and managing one or many APIs for use either privately, amongst partners, or to the public.
  • API Consumers - You are building websites, web applications, mobile applications, data analysis, data visualizations, or connecting devices to the Internet using APIs.

In an ideal world, everyone is both API provider, as well as a consumer—whether you are a business, organization, government agency, or everyday individual. APis impact everyone. Like money, banking and finances, you may not understand the inner workings of the financial system and economics, but you can balance your checkbook, and maintain a healthy credit score—with APIs, you may not understand the inner workings of APIs, oAuth, and the cloud, but you should know which applications you use on your phone, and which websites you’ve logged into with your Facebook account.

Everyone uses APIs. It is just a matter of whether or not they are educated, and aware of the world of APIs, underneath their feet.

A 101 View Of The API Landscape

API 101 stories dominate my blog, and it is important to me that any new user to the world of APIs can land on my home page, and find an introduction to the world of APIs. At the same time I want my expert readers, and everyone in between, to be able to find what they are looking for. I'm always working to expand my content beyond just my linear blog, and this section is looking to provide a 101 path through the API Evangelist network.

(start your API journey here)

Provide APIs (101)

Consume APIs (101)

  • Discovery (101) (research)
  • Authentication
  • Terms of Service (101) (research)
  • Integration (101) (research)
  • Software as a Service
  • Platform as a Service
  • Infrastructure as a Service
  • Backend as a Service
  • Embeddable (101) (research)


  • Aggregation
  • Reciprocity
  • Real-Time
  • Voice
  • Hypermedia
  • Containers
  • Spreadsheets

The Evolving Demand For Web APIs

As our appetites for data increasing, the demand for web APIs is evolving. The demand for APIs, is evolving directly in relationship to demand for Internet connected mobile phones, and devices that are spread across our personal and business lives.

  • Web - Early web APIs served up products, search, and other sales and commerce related information to web sites, distributed across the web
  • Mobile - Simple, lightweight APIs are delivering the resources needed by developers over high latency mobile networks
  • Devices - A wave new devices are emerging that use modern web API approaches to connecting physical devices to the Internet

We are still understanding how web APis are the preferred method for delivering content, data, and other resources for mobile developers, as we rush into applying the same approach to delivering, gathering, and aggregating resources in the Internet of things (Iot)—only time will tell if web APis, will meet the needs of Internet connected devices, as they have for web and mobile devleopment.

As with everything on my site, this API 101 material is a work in progress, and as each section becomes available I will link to it from here. My goal is to provide enough overview of the entire space, that anyone can get up to speed in 60 minutes or less, in very bite size chuks.

Let me know if there is something you'd like to see here, and would help you better understand the world of APIs.