this article Self Rimming Sink
Self rimming sinks, also called top mount sinks, are the most common sinks used in kitchens. A self rimming sink is mounted into the counter and held in place by an edge that protrudes over the opening in the countertop in all directions.
Of the types discussed here, self rimming sinks are the easiest to install. They also typically cost less than undercounter or apron styles (though not for all styles).
Undercounter Sink
An undercounter (or undermount) sink is installed below the counter surface, revealing the edges where the countertop was cut for installation of the sink. Because the edges of the counter surface are visible, undercounter sinks are usually not installed into laminate countertops. Undercounter sinks work best with solid surface or stone countertops which have edges that can be finished.
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