The function of a faucet cartridge is relatively simple. When you turn on the faucet handle, the cartridge moves a seal up or down, opening or closing the waterway. The seal is usually made of rubber or silicone, and it is responsible for preventing leaks when the faucet is turned off.

There are two primary types of faucet cartridges: compression and washerless. Compression cartridges are the traditional type and have been used for many years. They are made up of several parts, including a stem, washer, and O-ring. When you turn the faucet handle, the stem moves up or down, compressing the washer against the O-ring, thereby opening or closing the waterway.

Washerless cartridges, on the other hand, are a more modern design and are commonly used in newer faucets. They are also more durable and require less maintenance than compression cartridges. Washerless cartridges are available in two types: ceramic and cartridge-disc.

Ceramic cartridges are made of durable ceramic materials, making them long-lasting and resistant to wear and tear. They are also more precise than compression cartridges, allowing for smoother and more accurate control of the water flow and temperature.

Cartridge-disc faucets, also known as ball faucets, are the most common type of washerless cartridges. They are made up of a single lever that rotates to control the water flow and temperature. The lever has a series of holes that correspond to the hot and cold water inlets. When the lever is turned, the holes align to allow the water to flow through the cartridge.