Ok, First of all I'm building a large Lego City.  Yes, it's not Bachmann or normal electric train set.  Never the less I still need some basic understanding of proper controls to set my Lego trains up like a regular electric train.

Question:
Can anyone explain to me or get me the schematics of how the normal Electric train switch track?  How it works and operates?  How current gets switched to keep the train moving and not shorting out the track or train motors.

FYI:  I understand basic electronics.  It is my understanding though if the two currents touch than it'll short out  Hence, why I'm trying to understand how to reconfigure my Lego switch track.  To ensure safe/smooth operation.

FYI:  My city has it's own facebook if interested.   Search: Lego city dream build.
I would provide the link but I don't desire to offend anyone.