Today, we will build the API interface that can be consumed in real-time. For the language C++, Zortech (later Symantec, then Digital Mars), Watcom and Borland have all produced well known commercial compilers that have been used often with Win16, Win32s, and Win32. Some of them supplied memory extenders, allowing Win32 programs to run on Win16 with Microsoft’s redistributable Win32s DLL. The Zortech compiler was probably one of the first stable and usable C++ compilers for Windows programming, before Microsoft had a C++ compiler.

API functions

If we compare this to the documentation for the endpoint we’ll see that this matches the specified output for the endpoint. Immediately we can understand the structure of the data more easily – we can see that their are six people currently in space, with their names existing as dictionaries inside a list. In order to ensure we make a successful request, when we work with APIs it’s important to consult the documentation. Documentation can seem scary at first, but as you use documentation more and more you’ll find it gets easier. By going to your billing dashboard, then transaction history, you’ll see a list of your invoices.


The API describes and prescribes the “expected behavior” (a specification) while the library is an “actual implementation” of this set of rules. The average enterprise uses almost 1,200 cloud applications (link resides outside, many of which are disconnected. APIs enable integration so that these platforms and apps can seamlessly communicate with one another. Through this integration, companies can automate workflows and improve workplace collaboration.

API functions

File systems that use permissions—as they do on Windows, Mac, and Linux—have those permissions enforced by the file system API. A typical application doesn’t have direct access to the raw physical hard disk. Similarly, an API lists a bunch of operations that developers can use, along with a description of what they do. The developer doesn’t necessarily need to know how, for example, an operating system builds and presents a “Save As” dialog box. They just need to know that it’s available for use in their app. This list is far from exhaustive, and it will keep growing as developers continue to create innovative solutions that change the ways we live, work, and interact with one another.

What is API testing?

It’s more common for libraries to be explicitly loaded by the programmer. How the loading happens varies by programming language, but whenever you see import, include, or require in your output, it means the current program is pulling in another program’s API. The point of this example is that the window object is a part of the browser’s API.

  • Microservices is an architectural style that divides an application into smaller, independent components (also called microservices), connected using REST APIs.
  • The weather app on your phone “talks” to this system via APIs and shows you daily weather updates on your phone.
  • API documentation describes the services an API offers and how to use those services, aiming to cover everything a client would need to know for practical purposes.
  • We will be using the Fetch API, built-in to every browser for this.

Once we make a request to the API by using the ‘Test Endpoint’ button, we will also see the response directly in the browser. You don’t need to immediately write a program or launch api explanation a Postman application to get an idea of the capabilities of the API. Donations to freeCodeCamp go toward our education initiatives, and help pay for servers, services, and staff.

Tutorial: Install Linux on Windows with Windows Subsystem for Linux

DosWin32 and HX DOS Extender are other projects which emulate the Windows API to allow executing simple Windows programs from a DOS command line. Odin is a project to emulate Win32 on OS/2, superseding the original Win-OS/2 emulation which was based on Microsoft code. Other minor implementations include the MEWEL and Zinc libraries which were intended to implement a subset of the Win16 API on DOS (see List of platform-independent GUI libraries). An API is the interface that allows two independent software components to exchange information.

API functions

Thus, the .NET Framework and Java, likewise any other programming languages under Windows, are (or contain) wrapper libraries. We’ll be working with the Open Notify API, which gives access to data about the international space station. It’s a great API for learning because it has a very simple design, and doesn’t require authentication. We’ll teach you how to use an API that requires authentication in a later post.

API functions