1) Can someone explain to me Termination on SCSI and why it is necessary?

2) Does an iomega ZIP drive need to be terminated to work properly with a Mac Plus or Macintosh SE?

Thanks in advance. I have only used internal SCSI devices in the past, However, I keep hearing about termination/terminators, and my google-fu hasn't helped me (or was a little too upper class tech for me... sadly I'm a microsoft certified professional and A+ certified, but I don't recall much about SCSI from A+ and microsoft doesnt help much with apple :beige: )