Node.js allows JavaScript to be used for server-side applications by providing asynchronous and event-driven capabilities. It is commonly used for real-time web applications, messaging, and file downloads. Node.js uses a non-blocking paradigm and modules to break code into reusable pieces. Functions in Node.js are often passed as callbacks to handle asynchronous events and data without blocking the server.

1. Node.JS
Server side javascript

2. Intro

Good old javascript

But server side

Fully asynchronus

“Buzz” technology

3. Use cases

Real time web applications

Messaging

File download

Anything that spends lot of time waiting for
something

4. Differences from Web browser

CommonJS – http://wiki.commonjs.com

Modules

Npm – http://www.npmjs.org

File system, external process and network API

5. Programming paradigm

Non blocking operations

Functional programming

Lazy – doing only when needed

Event based

Do something when something happens

6. Example
HTTP server, which
serves movie.avi from
current directory

7. Modules

require();

exports functions and
variables from from
files module.exports

8. callbacks

most common code
construct

functions are
variables

non-blocking

“this” magick
– var self = this; trick

9. Thank you!