Simple. There's two kinds of VC. system.vc and map.vc.

System.vc is where functions and variables go. Do you want a place to hold the party's money? You declare it in system.vc. Your combat system, and all that sort of stuff would go in system.vc as well. Think of it as your system's VC. You can also use the #include directive to split system.vc into multiple files (for organization), but that's neither here nor there, so forget about that until later. ;)

Map VC is more geared towards events and your game's plot. This is where you'd script the stuff that Bob the Farmer would say when you talk to him. Every .map file has a .vc file of the same name. DarkCave.map reads DarkCave.vc for it's event scripts. Map VC is entirely made up of event blocks, like this:
event // 5 - Bob the Farmer
{
Text("Well, howdy.");
}

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'What you get by achieving your goals is not as important as what you become by achieving your goals.' -Zig Ziglar