Finish tabs are these concentrated rectangles of detergent you tuck in the main detergent cup of your washer. They come in different varieties and they sell some other dishwasher detergent products like rinse aid, but I just went with the cheapest tab version since I'm trying them out.
My glasses are still a little cloudy, but they're ancient and have been subject to hard water for around 10 years, so I'm hoping a few more washes with Finish will help.
I'll come down from my product plug now, but I wanted to give you a review of a product I'm enamored with. It really bugs me when my dishes look unclean. Nothing drive me more insane than cleaning and you can't tell.