Take a look at your dishwasher. You should see a small compartment for the detergent, and next to it, another small compartment. The second one is for the dishwasher rinse aid, which is a liquid composed of surfactants and salts and acids.
He dishwasher rinse aid It is designed to help your dishwasher work better, giving you cleaner, drier dishes that are all shiny and pretty.
Surfactants (short for "surface active agent") are probably the most important part of the dishwasher rinse aid. Water is a strangely codependent molecule: it likes to cling to its neighbors as much as possible. Water molecules on the surface get a little freaked out because they don't have water molecules to grab onto above them, so they doubly cling to their friends next door. This behavior is known as "high surface tension," and it's the reason why water clumps on glasses and plates: water prefers to stick to itself rather than spread out across the plate. An even simpler way to put it: a dishwasher rinse aid It makes the water “wetter,” more likely to spread or “bead up,” and (most importantly for your dishes), less likely to form the kind of beads that become water spots.
The importance of using dishwasher rinse aid
He dishwasher rinse aid This is especially important if you have hard water. You probably have hard water if there is a white residue around your faucets or drains, soaps and shampoos don't lather easily, or you see a ring around the tub. You'll probably also see poor cleaning results from your dishwasher, such as spots or film.
Surfactants can break up this high tension because they give those surface water molecules something to hold on to instead of their neighbors. So the water that used to pool on the glass spreads out in a thin layer. Water in a thin layer evaporates much more easily than water in droplets, so your dishes are dry at the end of the cycle.
Another important thing that the dishwasher rinse aid is to avoid water stains on the glasses. Added to this is the fact that dishwasher rinse aid prevents food residue from the washing water from falling back onto the dishes.
Another reason to use the dishwasher rinse aid is that it makes your dishes dry faster, which is helpful if you skip the heat cycle to save energy, or if you notice that your dishes are still wet when your heat cycle ends.