An application programming interface (API) is a set of tools that programmers can use to help them create software. Simply put, an API specifies how software components should interact. API interfaces are frequently used in a wide variety of fields and for a wide variety of purposes. To define the API concept in more detail, it is helpful to understand the basics.
Let’s continue with an example to understand better. Suppose you went to a restaurant for a meal and we made a selection from the menu.
From this point we forward your selections to the waiter to order. Then our selections are presented to the chef through the waiter, our food is prepared and it is returned to us. At this point we can ask ourselves, how was this dish prepared? This back and forth analogy is a starting point for this explanation.
Because with an API, we don’t really know what’s going on behind the order flow in the restaurant. All we know is that we order our food and the food we order is served to us by the waiter.
Now let’s continue with a real-life scenario example of how APIs work.
APIs are application interfaces that provide a fast, secure and controlled communication bridge between software or databases.
The way the API works is as follows.
- The receiving program makes a request (API Call). This request is processed as a request to the Web server via the URI.
- After receiving the request, the API calls the external program or web server.
- The server sends the requested information as a response to the API.
- The API passes the data it receives to the receiving program that made the request.
Imagine a library with a large, diverse range of books and documents. For example, in order to do your job, you need to get some data from this library on a regular basis. Let’s say that some floors or rooms of the library are not open to everyone because they contain private data, and those who want to obtain information are given a key that only opens the relevant doors within the limits of their authority.
The library security unit issues a key according to your authorization and gives it to you. With the help of this key, you can enter the floors or rooms where you can do your work, get information and carry out your work. Here the key given to you represents the API.
Thanks to this card, you can access the data in the sections opened to you as you wish, without ever visiting the security unit again. In this example, each key-holding visitor is also a client program.
Internet banking applications, which have been used very frequently recently, also work with the help of APIs. The application you install on your smartphone creates a bridge between your bank account information with the help of the API defined by the bank.
Allows you to make transactions in your bank account after API integration. Under normal circumstances, the bank’s operating system and software are different from the operating system and software on your phone.
The API allows for seamless operation and communication between these different operating systems and software. Thanks to APIs, even if the programming language or devices differ, processes run and a bridge is created.
With its ease of use, speed and security, the use of APIs in software development processes and applications has increased gradually. In this article, it is mentioned how the increasingly used APIs work and examples are given.