Teka Starbright 45 E-XN 1B RND 2-In-1 Installation Stainless Steel Sink is a type of sink that is mounted from above into a pre-cut hole in a countertop or work surface. It can be installed in two different ways: inset and undermount. Stainless steel sinks are a popular choice for kitchens due to their durability, corrosion resistance, and sleek appearance. 

Inset installation involves placing the sink into a pre-cut hole in the countertop. The sink's rim rests on the countertop, creating a visible edge around the sink. This installation method is relatively easy and can be done with a variety of countertop materials. 

Undermount installation involves attaching the sink beneath the countertop, so the sink's edges are not visible from the top. This creates a seamless and clean look, as the countertop material extends directly over the sink's edges. Undermount sinks are considered more aesthetically pleasing and easier to clean because there's no rim to catch debris.