Intellij IDEA has "exactly" the same functionality as webstorm as far as web is concerned?

Hi,

I would like to know what the differences as far as the web is concerned between intellij idea and webstorm.

I currently own and use intellij idea for android development and java.

I am interested now to start using nodejs and a little bit of angularjs. Now webstorm is being marketed for just this task...

But does Intellij IDEA include "ALL" funcionality from webstorm ?

Project files are compatible?

I am trying to find out if I need to buy webstorm, and also if I can follow the many tutorials for webstorm if I was using Intellij IDEA?

Anybody using both IDEs? Is so, why?

Thanks in advance