No laughing here. Now this is a general answer but it is where system (non-market) apps are installed/located. It is also where your framework among other things reside. If you were to install an app from the market it would be located in the data partition (just so you know the basic difference).
Well just looking at it real quick I noticed it does not list the Droid 4 as one of the devices it is tested on. The best thing I can suggest is to take a look through the thread for it and read up a little bit. Aside from that I am not sure what the risks involved would be, sorry.