The continuity test is the resistance check - if the resistance is less than 1 Ohm, it's likely the two things you're probing are connected to each other. Better multimeters have a setting that beeps when there's low resistance so you know what's connected and what isn't.
Proprietary front panel connectors really aren't where you want to learn about building computers: I would know as I started that way. You're better off trying to see how it is to replace the hard drive, CPU, RAM, etc., which will carry over to a new build.
__________________  "The computer programmer says they should drive the car around the block and see if the tire fixes itself." [src] |