If you find standing water in the bottom of your tub at the end of a cycle, you likely have a clogged dishwasher drain. Fixing this issue is often a straightforward DIY task that takes less than 30 minutes and requires basic household tools like a screwdriver, pliers, and a bucket.
If you have a small chrome cylinder sitting on your sink deck next to the faucet, this is an air gap. It prevents sink water from siphoning back into the dishwasher. how to fix a clogged dishwasher drain
Modern dishwashers have a removable filter at the bottom to catch large food particles. If this gets coated in grease, water won't drain. If you find standing water in the bottom