The terms “API” (Application Programming Interface) and “REST API” (Representational State Transfer Application Programming Interface) are related concepts, but they refer to slightly different things.
API (Application Programming Interface):
An API is a set of protocols, routines, tools, and definitions that allow different software applications to communicate and interact with each other. APIs provide a way for developers to access specific functionality or data from a software system without needing to understand its internal workings. APIs can be used to integrate different software components, services, libraries, and platforms.
APIs can come in various forms, such as:
Web APIs: These are APIs exposed over the internet using HTTP protocols. They allow different software systems to communicate and exchange data, which is a common approach for building services and applications.
Library APIs: These are APIs provided by programming libraries. They consist of functions, classes, and methods that developers can use to interact with the library’s features and functionalities.
Operating System APIs: These are APIs provided by an operating system to enable developers to interact with its features, like file system operations, memory management, and hardware control.
REST API (Representational State Transfer Application Programming Interface):
A REST API is a specific type of web API that follows the principles of the REST architectural style. REST is an architectural style that uses standard HTTP methods and status codes for communication between client and server. REST APIs are designed around resources, and each resource is identified by a URL. These APIs use HTTP methods like GET, POST, PUT, and DELETE to perform CRUD operations (Create, Read, Update, Delete) on these resources.
Key characteristics of REST APIs include:
Statelessness: Each request from a client to the server must contain all the necessary information, and the server doesn’t store any client context between requests.
Uniform Interface: A consistent way of interacting with resources using HTTP methods and URLs.
Representation: Resources are represented in a standardized format, often in JSON or XML.
Hypermedia: REST APIs can provide links to related resources, allowing clients to navigate and discover the API’s capabilities.
In essence, all REST APIs are APIs, but not all APIs are necessarily RESTful. REST is a specific design approach for creating web APIs that emphasizes simplicity, scalability, and uniformity. Other types of APIs can use different communication protocols, data formats, and conventions for interaction.
When talking about APIs, it’s essential to understand the context and the specific type of API being referred to.
