Pearl barley is ground whole-grain barley. This cereal name derives from the word "pearls" and it has long been named as pearl groats.
Boiled pearl barley is indeed valuable by its useful properties as a real pearl. Boiled pearl barley is a healthy dish for it contains proteins and starch, vitamins of group B, vitamins A, E, D, iron, calcium, copper, iodine as well as a lot of lysine.
This is a real depository of phosphorous needed for a mental activity (pearl barley contains 2 times much phosphorous than sea fish do).