Question About DCC vs. DC

[4-6-6-4 Challenger]

I think I understand the basics of this now.  I have an old DC train that runs around the christmas tree and I thought that I would have to do my whole layout like that in that I can only run 1 train at a time.  So basicly a turnout means nothing in DCC as far as the electircal side.  Where with DC the current means where the train is going to go.  Where in DCC the turnout means just the direction of the train is going to go.  Is what I said right?  Help me out please I am just new to this hobby I and dont full understand the DCC and DC part of it.

[60YOKID]

DC uses a simple variable direct current similar to battery current, to the track. Only one loco can be used at a time unless you break the track into sections called blocks.

DCC uses a digitally coded AC current, whereby you can control many locos at the same time. All the track is energized at full power all the time, and a "decoder" in each loco responds only to digital commands at it's own unique digital address.  These commands regulate the amount of power to the motor in that loco.

The two systems are generaly non-compatable. However, you can convert a DC loco to DCC operation by installing a decoder for $20-$50.

With DCC, turnouts can have all rails energized or can be what is called power routing.  But generally speaking, on most layouts all rails are energized all the time.