Application Programming Interface (API) is simply a set of rules that govern the communication between two devices. Not only do APIs allow different software to communicate, but they also manage the nitty-gritty of the conversation. In short, APIs are unique sets of instructions that enable and enhance cross-device, cross-software, and cross-platform communication.
Let’s take a quick example to illustrate the vital role played by APIs in the digital world:
Imagine any app on your phone that interacts with your phone camera. The developers of the app didn’t have to understand your camera functions. Thanks to APIs, they were able to create an app built on the camera’s existing framework.
APIs allow multiple software to merge seamlessly. Imagine APIs as power sockets that let different devices plug into an existing power grid.
Now that we’re through with API description let’s look at how API tools work.
How APIs Work
Before we begin, we must differentiate two things:
- APIs
- User Interface
A user interface is designed to communicate with a human user in language s/he understands. In short, the user interface sits between a human user and the machine. It converts human requests to machine-understandable language and converts machine responses to human-understandable language.
In contrast, API sits between the web server and a relevant application. A user makes a request via a software application. More often than not, the information requested is only accessible through a web server, that’s where APIs come into play.
APIs receive the request from an application and transmit the request to a web server. Every time you use your browser, and any other web-based app, APIs are responsible for linking your requests to the relevant servers.
That said, APIs are not limited to web-based applications. They are responsible for all communications between different machine-systems.
API Abstraction
In software engineering, abstraction is a principle that simplifies complex operations by only focusing on the highest-value details. Let’s take a quick example to illustrate this principle:
Imagine buying a book for a bookstore. The bookstore allows you to access your desired book immediately you visit. You don’t have to understand how the book was written and shipped to the location. All you need to do is visit the bookstore and make a request.
That’s what an API does. An application doesn’t have to understand how the web server operates. All the app has to do is to request an API. The request will be processed without application-server interaction.
API requests carry two main pieces of information:
- Request Type
- Credentials
Authorization Credentials
This piece of information is used to enhance the security of API requests. Absent of credentials, servers would quickly be attacked through mimicked API requests.
In a nutshell, APIs are central to a digital economy. They’ve made it possible for different software to work together for improved user experiences.
