Digital Command Control (DCC) is a standard for a system to operate model railways digitally. When equipped with Digital Command Control, locomotives on the same electrical section of track can be independently controlled.
The DCC protocol is defined by the Digital Command Control Working group of the National Model Railroad Association (NMRA). The NMRA has trademarked the term DCC, so while the term Digital Command Control is sometimes used to describe any digital model railway control system, strictly speaking it refers to NMRA DCC.
This is the latest and most sophisticated method of controlling model trains and is slightly more expensive than analogue control. It involves much less wiring though and allows multiple trains to be operated on one layout and even the same length of track.