When you install a new dishwasher one of the most important steps is connecting the drain line properly. There are different types of dishwasher drain connections depending on what else is mounted to the kitchen sink.
If you have an existing dishwasher it is usually easy to install a new unit by simply connecting the drain line the same way as the old one. But if you are changing the sink configuration the dishwasher drain configuration may also need to change. Before installing a new dishwasher it is a good idea to find out what the code requirements concerning the drain line are for your area. Then you'll know what your options are for the dishwasher drain.