REST API -two or more software components interact with each other

 

API stands for Application Programming Interface. It is a set of rules and specifications that define how two or more software components interact with each other. 

APIs are used to allow different applications to communicate with each other and share data.

APIs are used in a wide variety of applications, including:

• Web services: APIs are used to power web services, such as Google Maps API, Twitter API, and Facebook Graph API. These APIs allow developers to build applications that can interact with the underlying web services.
• Mobile apps: APIs are used to power many mobile apps. For example, a weather app might use an API to retrieve weather data from a weather service.
• IoT devices: APIs are used to connect and control IoT devices. For example, a smart home system might use an API to control a smart thermostat.

APIs can be either public or private. Public APIs are available to anyone who wants to use them. Private APIs are only available to authorized users.

To use an API, you typically need to get an API key from the API provider. This key identifies you as an authorized user of the API. Once you have an API key, you can start making requests to the API.

API requests are typically made using HTTP. The request body contains the information that you need to send to the API. The response body contains the information that the API returns to you.

APIs are a powerful tool for building and integrating software applications. By understanding how APIs work, you can build more efficient, effective, and scalable applications.

Here are some examples of how APIs are used in the real world:

• When you use a ride-sharing app to book a ride, the app uses an API to communicate with the ride-sharing company's servers. The app sends the pickup and drop-off locations to the servers, and the servers send back the estimated fare and arrival time.
• When you use a social media app to post a photo, the app uses an API to communicate with the social media company's servers. The app sends the photo and any accompanying text to the servers, and the servers post the photo to your profile.
• When you use a shopping app to purchase an item, the app uses an API to communicate with the retailer's servers. The app sends your shipping and billing information to the servers, and the servers process the payment and ship the item to you.

REST 

REST stands for REpresentational State Transfer. It is an architectural style for designing and developing web services. REST is based on the idea of using resources and their representations to provide a uniform interface for accessing and manipulating data.

RESTful web services are characterized by the following principles:

• Client-server separation: The client and server are separate components that communicate with each other using a stateless protocol.
• Statelessness: Each request from the client contains all of the information necessary to understand and process the request. The server does not maintain any state about the client between requests.
• Cacheability: The client can cache responses from the server to improve performance.
• Layered system: The system is composed of multiple layers, each of which has a specific responsibility. This makes the system more modular and easier to maintain.
• Code on demand (optional): The server can send executable code to the client to be executed on the client side. This can improve performance and flexibility.

REST is a popular architectural style for web services because it is simple, flexible, and scalable. It is also well-suited for distributed systems and cloud computing.

Here are some examples of RESTful web services:

• Google Maps API
• Twitter API
• Facebook Graph API
• Amazon Web Services API
• GitHub API

REST is a powerful architectural style for designing and developing web services

API is a broader term that refers to any interface that allows two or more software components to interact with each other. REST is a specific architectural style for designing and developing APIs.

RESTful APIs are characterized by their use of HTTP verbs to represent different operations, such as GET for retrieving data and POST for creating new data. They also use URIs to identify resources and JSON or XML to represent data.

Here is a table that summarizes the key differences between REST and API:

Feature	REST	API
Architectural style	Yes	No
HTTP verbs	Yes	No
URIs	Yes	No
Data representation	JSON or XML	Any format
Statelessness	Yes	No (optional)
Cacheability	Yes	No (optional)
Layered system	Yes	No (optional)
Code on demand	Yes	No

RESTful APIs are the most common type of API, and they are used by many popular web services, such as Google Maps API, Twitter API, and Facebook Graph API.

Here are some examples of RESTful APIs:

• Google Maps API: This API allows developers to retrieve and display maps, directions, and traffic information.
• Twitter API: This API allows developers to retrieve and post tweets, follow and unfollow users, and search for tweets.
• Facebook Graph API: This API allows developers to retrieve and post user data, publish and manage content, and manage ads.

RESTful APIs are a popular choice for developers because they are simple, flexible, and scalable. They are also well-suited for distributed systems and cloud computing.