Printer cartridges are small containers filled with ink or toner used in inkjet and laser printers. They are essential for producing printed documents and images. Each cartridge is designed to fit a specific printer model, ensuring compatibility and optimal performance. Cartridges come in various types, including black and color options. Ink cartridges typically contain liquid ink, while toner cartridges hold powdered toner. Users can replace cartridges when they run low on ink or toner, allowing printers to continue functioning efficiently. Proper disposal and recycling of used cartridges are also important for environmental sustainability.