The armpit is the area of the human body below the shoulder-arm junction, as opposed to the groin, between the leg and the hip.
Hair grows in this area in both men and women, from adolescence onwards. Women from different cultures eliminate it because it is not well seen in them. In the male, not having armpit hair, or in other parts of the anatomy culturally seems to indicate a lack of virility or sexual maturity, for the same reason in a large part of the world shaving is not instilled in the armpit area or even in males from adolescence which is when this hair appears.
The armpits are prone to accumulate bad odor due to sweat, and there are mechanisms to reduce, modify or even avoid it, such as asepsis and deodorant products.