An API (Application Programming Interface) is a set of guidelines that state how applications interact with each other. API calls allow you to communicate with these APIs.
Before we study what an API call is, let’s first discuss APIs.
The Application Programming Interface (API) is like a middle man connecting two sides. It is like a waiter who takes your order and brings you food, connecting the guests with the kitchen. So, it provides a channel that applications utilize to talk with each other. You put some information at one end, and the API takes that information and gets back with a result.
Today, countless APIs are available on the world wide web, providing access to all kinds of data. They have become essential to software applications today. You can use them to build web, desktop, mobile applications, CLI tools, extensions, etc.
Imagine that you are building a trading platform. You will need to support various features like exchange of currency, fluctuation of market rates, authentication, payment processing, and much more. Building and maintaining such functionalities is difficult. To resolve these issues, you can use integrations with various other software via APIs.
Now that we have a gist of what an API is and what it does let’s switch our attention to the API call.
API calls are like requests. Anytime a client requests some data from the server using an API, it counts as making an API call. APIs are integrated into almost all applications today, so these API calls are made frequently. For example, we have a time API to get the current time. Then, the process of requesting the API for the current time and getting a response back is called an API call. Try it yourself below to see how it works.
A complete API call usually consists of the following steps:
API Endpoint URL: Find the URL that you request.
Method: Set the HTTP method that you use to request the endpoint, such as GET, POST, PUT, DELETE, etc.
Headers and Authentication: Specify headers and authentication information.
Parameters: Specify parameters or data you want to send with the request.
Response: Get the response from the API.
In a nutshell, an API call is a process that takes place when you send a request to the API with the correct endpoint, method, and parameters. Your information is transferred, processed, and the result is returned back.