An incremental backup only copies those files which have changed from the previous back up. Each has its good and bad points. A full backup uses more space and takes longer to perform. Incremental back ups don't. In view of the speed of computers today I feel that everybody should do full backups every time followed by a compare.
Floppies Aah the good old floppy disk.
The Zip drive can hold 100Mb and the LS120 120Mb. The latter has the advantage of being backwards compatible with 1.44Mb and 720Kb floppies whereas the Zip Drive isn't. There has been some problems with the Zip Drive reported recently, the so called 'Click of Death', but I believe that these have been exaggerated. I have personally used a Zip Drive since they were released and it is still working fine. These allow you to back up quite large amounts of data fairly quickly and still take them away from the computer.