What is an API? (Beginners guide)
Tags: javascript, beginners, node, webdev
Published: 2023-01-06 00:07:17

Application Programming Interfaces, or APIs, are a set of guidelines that specify how two software applications should communicate with one another. 
An API acts as a bridge between two apps, enabling data exchange and communication between them. It also describes a collection of functions, as well as the inputs and outputs of those functions, that a developer may use to communicate with an application or service. 
Instead of having to create that functionality from scratch in their programs, this enables developers to access the functionality of an application or service from within their own programs. An operating system, database, web application, or other service may all be accessed by APIs.

There are many different ways that APIs can be used, but some common use cases include:

**Enabling communication between different systems:**
APIs can also be used to allow different systems to talk to each other and exchange data. For example, an e-commerce website might use an API to connect to a payment gateway to process transactions, or to connect to a warehouse management system to check inventory levels.

**Integration with third-party services:**
APIs can be used to access functionality provided by other companies. For example, a weather app might use an API provided by a weather service to get the current weather conditions for a particular location.

**Exposing a set of functionality to other developers:**
Many companies will create APIs to allow other developers to access certain features of their products or services. For example, a social media platform might create an API that allows developers to create apps that can post updates to users' feeds or retrieve information about users' friends.

There are several different types of APIs, they include:

**Remote Procedure Call (RPC) APIs:** 
These APIs allow a client to request that a remote server perform a specific task, and the server returns the result of that task to the client.

**Representational State Transfer (REST) APIs:**
These APIs allow a client to retrieve and manipulate resources on a server using HTTP requests. REST APIs are designed to be lightweight and easy to use, and are often used to expose data from web-based services.
(I will talk extensively about this than others)

**WebSocket APIs:**
These APIs allow for real-time, bidirectional communication between a client and a server over a single connection. WebSocket APIs are often used for applications that require real-time updates, such as online games or chat programs.

Here are a few more points you should know about APIs:

**API keys:** 
Many APIs require that developers obtain an API key in order to use the API. The API key is a unique string of characters that is used to identify the developer and track usage of the API.
When building third-party apps, this is particularly useful.

**API limits:**
Many APIs also have limits on how often they can be used. For example, an API might have a limit on the number of requests that can be made per hour, or the amount of data that can be transferred per month. These limits are often put in place to prevent excessive usage of the API and to ensure that the API remains available to all developers. 

**API documentation:**
Good API documentation is essential for developers who want to use an API. API documentation typically includes information about the functions and data types provided by the API, as well as examples of how to use the API.

That is just what you need to know regarding APIs. I will be creating most of my APIs using NodeJS but it is very important you have the basic understanding of what APIs are.
Should you have any questions, please feel free to ask in the comment section below.

Thanks for taking your time to read this.