The adjective granulated is good for describing things like sugar or salt that feel gritty or grainy. Something that's granulated is made up of many tiny pieces.
You're most likely to read the word granulated on the side of a bag of sugar, particularly if it's roughly milled. Think white or brown sugar, rather than powdered sugar. Sand is granulated, and so is ground coffee, and some grainy fertilizers you might spread on your garden. The gran in the word granulated gives a clue about its meaning — it comes from the Latin granum, which means "grain or seed."