Node.js

Node.js is a popular, open-source, JavaScript runtime environment that allows developers to run JavaScript on the server-side. Here's an overview:

*Key Features:*

1. Event-driven I/O model
2. Non-blocking I/O
3. Single-threaded
4. Cross-platform compatibility
5. Dynamic module loading
6. Extensive package ecosystem (npm)

*Advantages:*

1. Fast and scalable
2. Real-time data processing
3. Efficient handling of concurrent connections
4. Easy to learn for JavaScript developers
5. Large community and extensive documentation

*Use Cases:*

1. Web development (server-side rendering)
2. API development (RESTful APIs)
3. Real-time applications (live updates, chat apps)
4. Microservices architecture
5. IoT development
6. Desktop applications (Electron, NW.js)

*Node.js Frameworks:*

1. Express.js
2. Koa.js
3. Hapi
4. Sails.js
5. Nest.js

*Node.js Tools:*

1. npm (package manager)
2. yarn (package manager)
3. Webpack (module bundler)
4. Babel (transpiler)
5. Jest (testing framework)