It means (if true) that the GS150 can't do analog pass-through, i.e. take an analog signal from another source, e.g. a VCR, convert it to digital and pass it to the computer via the 1394/Firewire port. In other words, you can't use the camera to convert analog video sources to digital. Most likely, the camera will accept an analog input and allow you to record it to miniDV, which can then be played back with output through the 1394/Firewire port for capture. However, you should check the specs on the camera to make sure if you intend to use analog video sources for any purpose.