Most digital camcorders record video and audio on a Mini DV tape. The cassettes measure 2.6 x 1.9 x 0.5 inches (L x W x H), while the tape itself is only 0.25 inches thick. A Mini DV tape that is 65 meters long can hold an incredible 11GB of data, or 80 minutes of digital video.
The small size of Mini DV tapes has helped camcorder manufacturers reduce the size of their video cameras significantly. Some consumer cameras that use Mini DV tapes are smaller than the size of your hand. Because Mini DV tapes store data digitally, the footage can be exported directly to a computer using a Firewire (IEEE 1394) cable. So if you want to record video and edit it on your computer, avoid the SVHS and Hi-8 options and make sure to get a camera that uses Mini DV.