Compatible printer cartridge: These cartridges are not made by the printer manufacturer. They are designed bit differently than the original cartridge to avoid copyright infringement. Sometimes its done cleverly so that the cartridge fits in several printers of different model and brand. These 'compatible new' cartridges contain new components.
Some original printer cartridges are interchangeable. If you have a hp laserjet 4000/4050 printer, canon cartridge EP 52 will suite your printer. HP 27X and canon EP 52 cartridges are interchangeable and 'compatible OEM'.