Target Disk Mode

I recently discovered on my iMac G4 (running Tiger) in System Preferences/Startup Disk, that there is a thing called Target Disk Mode, wherein "you can connect [your computer] to another computer using a FireWire cable and use it as a hard disk." Now, my iMac is a bit old, it has only 800 Mhz and the video card may be outdated seriously in a year or so. If I were to use target disk mode to run it off of a new computer, say, a mac mini, would I get the advantages of increased speed and a new graphics card, or would I simply have more storage space?

Using target mode is just using the computer's internal disk as an external disk drive on another system. You are not booting from the disk, just mounting it for use on another system.

Basically so you can move data back and fore.

Thank you. I expected that would be true, but I was hopeful that maybe I might not need to get an entirely new computer when this one becomes too old. That being said, I don't suppose there's any way for me to use my iMac's screen as the screen for a new Mac mini.

I don't think it is possible.