They keep outer garments from being soiled by bodily secretions and discharges, shape the body, and provide support for parts of it. In cold weather, long underwear sometimes is worn to provide additional warmth. Some undergarments are intended for erotic effect. Special types of undergarments have religious significance. Some items of clothing are designed as underwear
Women may wear sports bras which provide greater support, thus increasing comfort and reducing the chance of damage to the ligaments of the chest during high-impact exercises such as jogging.
In cold climates, underwear may be an additional layer of clothing that helps the wearer keep warm. Underwear can be used to preserve the wearer's modesty – for instance, some women wear camisoles and slips (petticoats) under clothes that are sheer. Conversely, underwear can also be worn for erotic effect. It is possible to purchase underwear made specifically for sexual titillation, such as edible underwear and crotchless panties.
Bras and underwear serve more purpose than just being sexy and cute. Bras help support the breast and decrease sagging, backache, and pain while jogging/excercsing/etc. Underwear also serves more purpose than just being cute - it helps protect you from irritation of pants rubbing against that sensative area, when their made of the proper materials they help the area breathe better, and they help with discharge and for women who use pads during their menstrual cycle.
underclothing has been a part of culture for a loooong time. Petticoats and all that just got smaller and smaller over the years. But I can tell you for sure that thongs were invented by strippers in NYC in the 1930s because the mayor demanded that they clean up their "acts"