How are sucrose (table sugar) and the starch in flour chemically related? what makes them different from each other?

Both the sucrose (table sugar) and the starch is composed of glucose molecules C6H12O6. They are made up of monosaccharides. Both are covalently bonded with glucose molecules. The only difference is that sucrose is made up of the disaccharide sucrose but starch is a polysaccharide.