Granulated sugar is the common refined sugar, which is made either from sugarcane or sugar beet. So, it is basically sucrose. Earlier, sugar used to come in the form of solid loaves or blocks, as it was impossible to prevent the sugar crystals from clumping together. The sugar crystals tend to stick together due to high moisture content, and form blocks. Such loaves of sugar have to be broken apart, and then crushed a bit before using as a food additive.