The choice for kitchen sink mounting styles have not changed much over time but it is not something that most people have to deal with on a normal basis so most people do not really know what options are out there today. Rushing into this choice, just like any other choice in the kitchen, can lead to wasted money and possible years of living with something you do not really want.
An under-mount kitchen sink, also called bottom-mount, is called that because they are installed below the countertop surface. The installation method is also the cause of the biggest strength and weakness of this mounting style.
The biggest advantage of an under-mount sink is how easy they are to clean up the kitchen with. Because the sink is mounted under the countertop it makes cleaning as easy as just brushing the countertops off into the sink which is great for most families now-a-day because most families are always on the go.
The fact that is mounts under the countertop leads to it's biggest drawback as well which is it is harder to install and not really recommended for the wide variety of countertop materials like a self-rimming sink. In general, installing an under-mount sink is not something a normal do-it-yourself will be able to do on his or her own. The ideal material to make the countertops out of to make best use of an under-mount kitchen sink is some sort of stone: granite, marble, or an engineered stone (granite typically being considered the best). Some of the cheaper countertop materials are not really ideally suited for this type of sink.
Under-mount sinks start a little bit higher than a self-rimming sink and are also going to be more expensive to install but they are a little bit more hassle free then the more commonly used self-rimming sink. The biggest resellers of under-mount sinks are Kohler and Blanco and they can be found in all of the common sizes of other types of sinks.