There are four basic types of kitchen faucets: ceramic disk, cartridge, ball, and compression.
Ceramic Disk Faucets
Single-handle, disk-type faucets operate a pair of ceramic disks that slide over each other to regulate water flow and temperature. These faucets are typically the most durable and trouble-free. The disks and mixing chamber are housed in a large cylinder held in place with screws.
Cartridge-type faucets come in both single- and double-handle configurations. Designed for ease of repair, the flow mechanisms are housed in a cartridge that can be replaced when leaks occur.
Single-handle, ball-type faucets have a rotating ball inside that moves over water inlet holes and permits water to flow, regulates the flow of hot and cold water, and shuts off the water altogether.
These faucets were common in the early 1900s. Each of two handles turns a large screw, or stem, inside the faucet. The stem has a washer on one end that's positioned over the hole through which water flows. When screwed down tight, the washer blocks the flow.
A Final Tip
Solid-brass, die-cast innards indicate a high-quality kitchen faucet -- but also an expensive one. If you're in the market for a less-expensive option, beware of faucets with plastic shells or handles. Their price may be attractive, but their durability and resistance to scratches are likely to disappoint.