An API works through communication between different codes, thus defining specific behavior of certain objects on an interface. That is, the API will connect several functions on one website (such as search, images, news, authentications, and so on) to enable it to be used in other applications.

Operating systems also have APIs, and they still have the same function. Windows, for example, has APIs such as the Win16 API, Win32 API, or Telephony API, in all its versions. When you run a program that involves some process of the operating system, it is likely that we make a connection with one or more Windows APIs. To clarify the concept of an API, we will give go through some examples of how it works.

On Windows, it works on an application that uses the system clock to display the same function within the program. It then associates a behavior to a given clock time in another application, for example, using the Time/Clock API from Windows to use the clock functionality on...