Villi are tiny projections from the lining of the ileum in the small intestine (where absorption takes place).
Villi have thin cell walls and are only one cell thick, so the food particles don't have as far to travel in the blood.
Villi have a rich blood supply, this helps to carry the absorbed molecules away from the intestine quickly which means there is a low concentration of food molecules in the blood.
Villi and microvilli increase the surface area in the small intestine.
Villi contain lacteals which carry fat droplets separate from the rest of the food particles as they don't dissolve well in blood.