Your CAD program is used to make a drawing (Computer Aided Design).
Your then import this into your CAM program (Computer Aided Manufacturing).
You set things like your tool diameter, speeds and feeds in your CAM software (turn the coolant on etc) and the CAM software reads your CAD drawing and figures out where to send the tool.
You the hit the Post Process button and the CAM software generates the G-Code for your machine (each machine has a different Post Processor cos they mostly have different G-Codes so you need the right Post Processor for your machine).
You then take the G-Code file to your machine by floppy or direct transfer.
Upload the G-Code to your machine, dry run it with the tool well away from any metal to make sure you're not gonna ramp into the machine table, then cut some parts
I love deadlines- I like the whooshing sound they make as they fly by.