Sebaceous glands make oily lubricants for the skin and the hair of hunams and animals. they are located in the hair follicles of the skin but do also occure in hairless areas except the palms of your hands and the soles of your feet.
No. Sebaceous glands produce a grease-like substance called sebum which is excreted onto the skin. They are why you get greasy if you get too far from a shower for a couple of days.