Introduction to Node JS

Node JS is created by Ryan Dahl with the aim of creating real-time websites with push capabilities.It is an open soure, cross platform runtime environment for server-side and networking applications.
Node JS uses V8 engine.Node JS is an asynchronous language.It is lightweight and efficient because of it's event-driven ,non-blocking I/O nature.Normally uses for 

• I/O bound appications. 
• Data treaming applications.
• Data intensive real-time applications.
• JSON API based applications.
• Single page applications.

Not the best platform for CPU intensive heavy computational applications.It is capable of handling a huge number of simultaneous connections with high throughput.Node js is single  threaded. It not create new thread for each connection.

Advantages of Node JS

• easy to scale both horizontal and vertical
• high performances - because V8 engine compile the JS code into machine code directly.it caching modules into memory after the first use.
• easily extensible
• has many reusable modules - npm package manager has large no of modules.
• support for common tool like unit testing.

disadvantages

• has many libraries but no of robust libraries are comparatively low.
• not suitable for computational intensive tasks.

How to install Node JS

1. go to node js web site and download node js windows installer.
2. run the installer and install node JS.
3. restart....
4. open cmd window and type node -v or node --version to assure that node js is installed.if installed it shows the version of node JS that you installed.(v6.10.0 or something like that..).
5. open cmd window and type npm -v to assure node package manager(npm) is installed.if successfully installed it shows the version of npm that you installed.(3.10.10 or something like that..).
6. to test open notepad or any text editor and type conosle.log('node JS is installed')and save as <any name>.js(asd.js)

1. now open cmd and go to the directory that you saved .js file and type node <name_of_file>.js.now you can see "node JS is installed" text in cmd.
2. that means you have successfully installed node js....