what exactly does it mean that the DOW is down 250 points right now? what would a "collapse" look like? what is a collapse? the US dollar value is zero? what would this look like in our country the day it happens? 7 days? 30 days?

because i understand a collapse of the current financial structure WILL happen and its likely beginning to take its last breathe within the next 30-60 days. so i was hoping someone could put into perspective what exactly are the dynamics of what is going on economics wise at the moment .

thanks!