Firmware is the program that controls the dvd player and lets it know how to best play dvd, vcd or mp3`s etc. The dvd player will already have firmware in it, but many players (like the SCAN) allow you to update the firmware by putting a cd in the drive. The advantage is that bugs can be fixed, and imporvements can be made to picture and sound quality. The disadvantage is you can load the wrong type and your dvd player may not work properly or even at all
SteveC