What is the Difference Between Similar But Different Things, Terms, and Objects

What is the Difference between Fructose Sucrose Glycogen Glucose and Galactose

We need carbohydrates in an appropriate proportion on daily basis along with vitamins, protein and fiber and sugar is the best source of providing carbohydrates. Sugar is the major constituent of our daily diet and we cannot imagine our life without sugar. However, sugar is available in different forms like Fructose, Sucrose, Glycogen, Glucose and Galactose.