Hi,
The online help does not go into great detail on this subject - see https://app-help.vectorworks.net/2021/eng/index.htm#t=VW2021_Guide%2FConnectCAD%2FEditing_devices_and_sockets.htm
We say that "The ConnectCAD template contains sets of classes with names that clearly indicate their function. The classes can be edited to change the appearance, font style and color, etc. of various ConnectCAD objects for a customized look." If that's not detailed enough, I can add more information in the future.
FYI, I searched for "signal types" which got me to "Adding sockets, loops, and terminators" and from there I clicked on "Editing devices and sockets."
Alexandra
Manager, Technical Publications