kinds of facuets hole on the bathroom cabinet basin

there are three kinds of bathroom vanity unit depend on the basin location, above-basin bathroom vanity,  ressed bathroom vanity, mounted basin bathroom vanity.

above-basin bathroom vanity, ressed bathroom vanity, the faucet fix on the counter top, or fixed in the wall.

mounted basin bathroom vanity,  we have single faucet hole or three holes. single faucet hole, hot pipe and cold pipe all in the body of faucets , use screw to fix the faucet on the counter top.

three hole basin, lef and right handle to control the hot water and cold water, and the middle hole is for faucet to waterflow.