Okay, so you know how sometimes you like to put stickers on things, like your notebook or your bike? Well, grown-ups have stickers too, but they are called decals. A ceramic decal is a special kind of decal that is made to be put on dishes or other ceramic things like mugs or plates.
First, someone makes a picture or design on a computer or with special art materials. Then, they print the picture onto a special kind of paper called ceramic decal paper. The paper is very thin and delicate because it needs to stick onto the ceramic thing without ripping.
Next, the person takes the decal paper with the picture on it and puts it on the ceramic thing they want to decorate. Then, they use a special kind of machine that heats up the ceramic and the decal paper. This makes the picture melt onto the ceramic and stick to it really well.
Finally, once the ceramic and the decal have cooled down, the ceramic thing now has a very pretty design on it that won't come off even if you wash it in the dishwasher!