API stands for Application Programming Interface. It is a set of rules and protocols that allows different software applications to communicate and interact with each other. APIs define how different components of software systems should interact, specifying the types of requests that can be made, the format of the data to be sent, and the expected responses.
REST API (RESTful API), which stands for Representational State Transfer API, is a particular architectural style for designing networked applications. It is based on a set of principles and constraints that promote scalability, simplicity, and interoperability. REST APIs use the HTTP protocol as their underlying communication protocol and leverage its methods (GET, POST, PUT, DELETE) to perform different operations on resources.
REST APIs operate on the concept of resources, which are typically represented as URLs (Uniform Resource Locators). Each resource has a unique URL, and different operations can be performed on these resources by sending appropriate HTTP requests to their respective URLs. For example, to retrieve information about a user, you would send an HTTP GET request to the user's URL.
REST APIscommonly use standard data formats such as JSON (JavaScript Object Notation) or XML (eXtensible Markup Language) to represent data in the requests and responses. JSON has become the most popular format due to its simplicity, readability, and wide support across various programming languages.
REST APIs are stateless, meaning that the server does not store any information about the client's previous requests. Instead, each request contains all the necessary information for the server to process it. This allows for scalability and enables the server to handle a large number of clients concurrently.
In summary, a REST API is a type of API that follows the principles of the REST architectural style. It uses HTTP methods and URLs to perform operations on resources and typically communicates using JSON or XML. REST APIs are widely used for building web services and enabling communication between different software applications.