As packaged, sugar granules are smaller and more deformed than salt grains. When dissolved sugar is allowed to dry it forms interesting patterns. When it first dries it forms a kind of sticky "goo" without much structure, but after a week or so the goo dries completely forming patterns like the one seen below.

Sugar was "refined" in the sixth century by monks who used the purifying properties of charcoal. What we call "table sugar" or just "sugar" is actually sucrose, one of about 100 substances known as sugars. Sucrose is the most common sugar found in plants, and most plants contain at least some of it. Sucrose is a "disaccharide" with the formula C₁₂H₂₂O₁₁. There are also monosaccharides, such as dextrose and fructose, with the formula C₆H₁₂O₆. [there are oligosaccharides and polysaccharides as well, but these are less familiar to most people.] The difference between the sugars within the 2 categories is the structure, how the atoms are arranged. Dextrose and Fructose, for example, contain the same number and types of atoms, but the atoms are arranged differently. This diffrence in arrangement affects how they interact with other compounds. This principle is illustrated by the fact that while Sucrose and Lactose are both C₁₂H₂₂O₁₁, anyone not suffering from diabetes can easily digest sucrose but most adults have trouble digesting lactose!

Sucrose is actually composed of a molecule of dextrose and fructose with a molecule of water removed. Enzymes in human saliva cause it to absorb a molecule of water and revert back to dextrose and fructose, in this form it is called "invert sugar". This is essentially what honey is, the distinctive taste of different varieties being caused by various impurities.