Most printers operate on color or black ink cartridges. Some printers will use one cartridge that contains many colors for color printing while many inkjet photo printers will use individual ink cartridges for each separate colors. Over time, this is a good way to save money as you only have to change the cartridge of the color that runs out.
Some inkjet printers use up to eight individual color cartridges. Separate color cartridges also help to give your prints more true-to-life colors. There are several types of ink to use.
Pigmented inks dry quickly and don't fade as much as dye based inks. Dye based inks supply excellent color, but aren't water resistant or as quick drying as pigment based inks. Archival inks are also used and they resist fading pretty well. If you are printing with archival ink you should also use archival paper.
When your ink cartridges run out you can refill them or buy new ones. Make sure that refilling your cartridges won't affect your warranty. Ink cartridges can range in price from about $10 to $200.