OK, this isn’t the most thrilling subject in the world but it is worth understanding to avoid wasting time and money having to re-wash the same load over and over again.
A dishwasher is a powerful appliance but it obviously has limitations. In order for it to effectively wash your dishes water needs to be able to circulate freely around the items in order for everything to receive a thorough clean. Utilising the inbuilt racks will normally ensure that plates, glasses etc are sufficiently spaced out. The problems normally arise with more awkward items such as casserole dishes and saucepans.
The above video from VideoJug will hopefully explain how best to stack the load so everything comes out sparkling clean with no bits of food clinging tenaciously onto your plates.