Re: what does the sebaceous gland do?

You already know that the function of sebaceous gland is to secrete an 
oily substance. Actually the purpose of this oily secretion is to protect 
the skin from getting dried and scaly. Otherwise the skin after getting 
dry would shed off. So you can see here that these are the functions of 
sebaceous glands which they perform using the oily secretion. Your 
confusion might be concerned with the oily nature of skin imparted by 
these glands that is certainly embarrassing especially for youngsters. 
However they are essential and they are significant for not letting us 
face any dryness problems in dry weathers.