It’s now clearer what an API is, its characteristics, and the different types. But to better understand APIs, you should go through how they work
1. Client application via API calls
A call to an API includes everything that takes place after sending a request, such as when the API gets data from the server and sends it back to the client. Sending a request to an API server is called a client application. There are different request methods, usually in URL format, since HTTP controls the communication between server and client.
Clients expect the server to perform basic functions. These involve retrieving resources, creating a new one, editing or updating an existing record, and deleting one. Clients typically make four basic requests: get, post, put, and delete.
For example, when booking a flight online, APIs execute functions. APIs go through the server’s data to check for available flights and create a booking for you when there’s a vacancy. If you need to change flight details, APIs allow you to make updates, or they can cancel the entire booking when desired.
2. API connects an application to a web server
API is the middleman between the application and the server. Similarly, the waiter is the middleman connecting the customers to the kitchen in a restaurant. The waiter takes orders from the customers and brings them to the kitchen for the chef to prepare. In the same way, APIs stand in to support transactions between apps and servers.
When you use Facebook, for instance, APIs step in to do their job. Facebook talks to other systems to get and verify data through APIs. This process permits Facebook users to use their log-in credentials, access their profiles, and do what they want in the app. The same applies to other apps. They communicate with different systems and the web server through their respective APIs.
3. A response is delivered to you
Going back to the analogy of the waiter being the API between the customer and the kitchen, the end response is that the waiter delivers the food to the customer. Technologically speaking, the API is the messenger that provides the request and brings the response back to you.
Take YouTube as an example. You gain full access to YouTube’s enormous video library and add functionality to your website or app using YouTube’s APIs. They allow you to search content, stream videos, and create playlists, among other things.