What is an API in simple explanation

 

An API (Application Programming Interface) is a set of rules and protocols that allows different software applications to communicate with each other. It defines how different software components should interact, making it easier for developers to integrate and use the functionality of one software system in another.

 

Example1: API in Layman words:

Ø  Think of it as a waiter taking your order at a restaurant.

Ø  You (the client) don't need to go to the kitchen and cook the food yourself (interact directly with the server).

Ø  Instead, you communicate your order to the waiter, who then conveys it to the kitchen and brings the food back to you.

Ø  Similarly,in SAP, different software systems or applications (like a website, mobile app, or third-party software) may want to access or use data and functions from SAP systems.

Ø  The API acts as the intermediary or waiter, allowing these external systems to make requests (place orders) for specific data or actions from the SAP system. The SAP system processes the request and provides the necessary information, just like the kitchen preparing your food.

 Example2:Simple API flow how it works in a Restaurant:

                       In this way, APIs facilitate smooth communication between different software, enabling them to work together seamlessly, even if they are from different vendors or serve different purposes.

There are several types of APIs, and they can be categorized based on their purpose and how they expose functionality. Here are some common types of APIs with examples:

Open APIs (Public APIs):

Definition: Open APIs, also known as public APIs, are accessible to developers and third-party applications with minimal restrictions. They are designed for external users and developers and are publicly available.

Example: Twitter API, Google Maps API, OpenWeatherMap API.

Internal APIs (Private APIs):

                   Internal APIs, or private APIs, are used within organizations and are not exposed to external developers. They are designed to improve code reusability, maintainability, and collaboration among internal teams.

Example: An e-commerce company using internal APIs to connect their inventory management system with their order processing system.

RESTful APIs:

                      REST (Representational State Transfer) is an architectural style for designing networked applications. RESTful APIs adhere to the principles of REST and use standard HTTP methods (GET, POST, PUT, DELETE) for communication.

Example: GitHub API, Dropbox API, Facebook Graph API.

SOAP APIs:

                SOAP (Simple Object Access Protocol) is a protocol for exchanging structured information in web services. SOAP APIs use XML for message formatting and are known for their strict standards.

Example: Web services in enterprise systems like SAP, Salesforce, or Microsoft Dynamics.

GraphQL APIs:

                   GraphQL is a query language for APIs that allows clients to request only the data they need. It provides a more flexible and efficient alternative to traditional REST APIs.

Example: GitHub GraphQL API, Shopify GraphQL API.

Webhooks:

                    Webhooks are a way for one system to provide real-time information to another system by sending HTTP callbacks or notifications when an event occurs.

Example: GitHub Webhooks for receiving notifications about repository events, Stripe Webhooks for payment events.

Library-based APIs:

                Library-based APIs provide a set of functions and procedures that can be used by applications. They are often packaged as libraries that developers can include in their code.

Example: Java Standard API, .NET Framework Class Library.