To a Canon printer cartridges that work with this model, it is both a consumable (toner cartridge) and a replacement part (drum). However, the drum is an essential part of a laser printer. So using an "original part" avoids problems and can extend the life of the printer beyond its standard duration. My Canon LBP-800 in September 2000 still works perfectly after 15 years of use and the average lifetime of a cartridge is about 3 years for my use.