According to WebMD, hair is made up of keratin, protein, which is produced in hair follicles. As follicles produce new cells, the old cells are pushed out through the surface of the skin at around 6 inches per year.
You may call this the growing of hair.
But in fact, a strand of hair you see is a string of dead keratin cells.
The average adult head has 100,000 to 150,000 hairs and loses up to 50-100 hairs per day. So if you're losing up to 100 hairs per day, you shouldn't be worried.
There are other solutions that can promote hair growth, but for now, just take look at the hair growth cycle.