Modules are built in the Virtual Hardware Builder when its set to Module Mode. A Module consists of 1 or more Components and any stylisation you wish to make such as borders, Snippet Label Placeholders etc.
All known Components are listed in the Items Panel on the right hand side. Simply click and drag the Component you wish to add to the Module.
Its recommended to leave the Module background colour as transparent as this provides maximum flexibility such that the Module will pick up the Device Panel background colour instead of being fixed.
Watch the video example for more information.