For most printers, you have the option of purchasing ink cartridges that are manufactured by the manufacturer of the printer known as genuine or original cartridges, or of purchasing compatible ink that is produced by a third party. For example, if you need Epson inkjet ink, you can either purchase brand-name Epson print ink or you can purchase cheap Epson ink that's manufactured by a company that offers compatible products. Generally speaking, there are few differences between the two options.