🐸 Node.js essential training

https://nodejs.org/docs/latest/api/

Node.js is an open-source, cross-platform JavaScript runtime environment that executes JavaScript code outside of a web browser. It's ideally suited for event-driven, non-blocking applications that require real-time communication. Here's a breakdown of its core concepts:

1. JavaScript on the Server

• Traditional Web Development: In the traditional web development model, web servers like Apache or Nginx serve static HTML files or use server-side languages like PHP, Python, or Java to generate dynamic content. The browser then interprets and executes JavaScript code for interactive elements.
• Node.js Revolution: Node.js allows you to write server-side applications entirely in JavaScript, using the same language you're familiar with for front-end development. This unified approach streamlines development and fosters code reuse.

2. Event-Driven Architecture

• Node.js is built upon an event-driven architecture, where code execution is triggered by events (signals or messages) rather than a linear sequence of instructions. This enables efficient handling of asynchronous operations, such as network requests and file I/O, without blocking the main thread.

3. Non-Blocking I/O (Input/Output)

• Unlike traditional languages that might wait for I/O operations to complete before continuing, Node.js utilizes a non-blocking approach. It initiates the I/O operation and then moves on to execute other tasks while the I/O operation is in progress. Once the I/O operation finishes, an event is triggered to notify the code, allowing it to handle the result. This makes Node.js highly performant for applications that deal with a lot of concurrent requests.

4. Asynchronous Programming

• To manage non-blocking I/O effectively, Node.js employs asynchronous programming techniques. This involves using callbacks, promises, or async/await (introduced in later JavaScript versions) to define what should happen when an operation is complete (asynchronous) rather than waiting for it to finish before proceeding (synchronous).

5. The V8 Engine

• Node.js leverages Google Chrome's V8 JavaScript engine, which is known for its exceptional speed and efficiency. This engine converts JavaScript code into machine code for direct execution by the computer's CPU.

6. Modules and Packages (Node Package Manager - npm)

• Node.js applications are organized into modules, which are reusable blocks of code. Modules can be created using the module.exports syntax and imported using the require() function.
• Node.js comes with a built-in package manager called npm (Node Package Manager). npm allows you to discover, install, and manage third-party JavaScript libraries and frameworks from the npm Registry, which is a vast repository of open-source code.

7. Common Use Cases for Node.js

• Real-time Applications: Node.js excels at building real-time applications like chat applications, collaboration tools, and multiplayer games due to its efficient handling of concurrent connections and event-driven nature.
• Microservices Architecture: Node.js is well-suited for building microservices, which are small, independent services that communicate with each other to form a larger application. This approach promotes modularity, scalability, and maintainability.
• APIs (Application Programming Interfaces): Node.js is a great choice for creating RESTful APIs (web APIs that adhere to the Representational State Transfer architectural style) that provide data and functionality to other applications.
• I/O-Bound Applications: Node.js shines in scenarios involving a lot of I/O operations, such as file processing, database interactions, and network requests, as it doesn't block on I/O, keeping the main thread free to handle other tasks.