This is a hobby requiring a combination of skills, talent, fellowship, and mutual enjoyment in developing a simulation of a working railroad (..the trains do more than go around in a circle). A module is a portable section of table type structure which is but one part of a large group of like tables which when all assembled together form a large and fully operating model railroad. 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. Young or old, the attraction for this pastime continues endured over the ages. We are primarily concerned with the HO scale 3.5 mm (0.1378 in) represents 1 real foot (304.8 mm)  which is the most popular.