Undermount Sink Installation
Under-mount or bottom-mount sinks are installed below the countertop surface. The edge of the countertop material is exposed at the hole created for the sink (and so must be a carefully finished edge rather than a rough cut). The sink is then clamped to the bottom of the material from below.
Advantages of an undermount sink include superior ergonomics and a contemporary look. This requires a counter material that can have a polished edge around the sink opening (quartz, granite and marble are beautiful options).