These are the pores of a plant. Apple lenticels can be distinctive and decorative. Apples breath and transpire through these pores, which may be portals of russet and disease.
Some varieties are susceptible to a blight known as lenticel breakdown, which mars the fruit with ugly brown pitting. Lenticel breakdown is especially troublesome for the apple industry as it does not manifest until after packing. It can be aggravated by washing and by some of the chemical treatments to which commercial apples are routinely subject. Gala is especially vulnerable.