Final answer:
Vitamins are organic compounds that our bodies need in small amounts and are classified into water-soluble and fat-soluble categories.
Step-by-step explanation:
Vitamins are organic compounds that our bodies need in small amounts and cannot synthesize on their own, so they must be obtained from the diet. They are classified into two categories: water-soluble vitamins and fat-soluble vitamins. Water-soluble vitamins, such as vitamin C, are not stored in the body and need to be consumed regularly. On the other hand, fat-soluble vitamins, like vitamin A and vitamin D, can be stored in the body's fat tissues.