Asynchronous Behavior of Node.JS

Question

I am just beginner in enhancing my horizons about this obscure technology.

 

From earlier pertinent articles which I read for this technology, I come to know that it provides facilities like asynchronous execution.

 

Addtionally from some articles I also come to know that it is Single threaded application.

 

So my final question would be how can single threaded application perform asynchronous execution ?

 

Simple explanation would be more appreciated.