What is the difference?

There are differences between the different sugars. When we eat
sucrose(sugar in candy etc.), our bodies quickly break it down into roughly equal parts of
glucose and fructose. Glucose is the sugar our bodies use for both
physical and mental energy. When our bodies sense an increase of
glucose in the blood, it immediately directs the pancreas to push
insulin into the blood stream. With the insulin, the body is able to
burn the glucose as energy. If there's too much glucose in the blood
stream to be used as energy, the glucose can be changed to glycogen,
the body's short-term storage energy supply. And if the glycogen pool
is already full, the body will turn it into long term storage in the
form of fat.
Different blood-sugar effects possible after
eating a high concentration of sucrose sugar.

Fructose is broken down by the body slowly and is converted into
SUCROSE and GLYCOGEN. Fructose is often recommended for, and consumed
by, people with diabetes mellitus or hypoglycemia, because it has a
very low Glycemic Index (GI 23) relative to cane sugar.