A range of styles of bras exist, and are worn based on a variety of situations. The amount of support varies between styles. Some bras are designed from a highly practical point of view (structural in their support), and while others are designed to provide a deliberately sexual, sensual, erotic and alluring form. Many bras can be placed into more than one category such as a maternity bra that is also designed to provide the lift that push-up bra would.
Built-in bras, also known as shelf bras, are a supportive structure on the inside of another garment (i.e., a swimsuit or tank top), which provides support for the bust without the need for a separate bra. In most garments, these consist of a horizontal elasticated fabric strip. There are some shelf bras that do have cups and underwires similar to the other bra types.
Bullet bras are a type of full support bra with a round tip at the end of each cup of the bra (the shape of the cup is similar to a bullet). Bullet bras were invented in the 1950s and were popular wear by the actresses of that era.
Demicup bras have lower cut cups, covering approximately half of the breasts. Some styles of demicup offer the same or more support than the full coverage bras, and they enable low cut garments to be worn without the bra being seen. The demi cup bra is sometimes referred to as a balconette bra. Demi-cup bras may be designed to provide lift in a manner similar to a push-up bra.
Full support bras are a type of bra designed to offer good support for the whole of the breasts, and as such are a typical, practical bra for everyday wear.
Mastectomy bras are designed so that a prosthesis may be held in place to simluate a human breast. The mastectomy bra is intended for women who have lost one or both breasts in mastectomy treatment for breast cancer or other serious breast diseases.
Maternity bras are slightly different from nursing bras though the terms are sometimes used interchangeably. Maternity bras are designed so that they can be expanded to adjust as the breasts increase in size over the course of a pregnancy.
Minimizer bras are designed to de-emphasize the bust, in particular, of large-breasted women. Minimizers, by compressing and reshaping the breasts, help to create the illusion of being a cup size or two smaller.
Nursing bras are designed to help make breastfeeding simpler by allowing for easy access to the nipple. Traditionally, nursing bras are made with flaps of fabric over the cup which can be unclasped and pulled down to access the nipple of the breast. Even with the "flap" pulled down, the cup of the bra supports the breast. There are also no flap versions made of stretchable fabric which can pulled to the side when it is feeding time. Underwire versions of nursing bras are discouraged because they can constrict the breast and can cause either blocked ducts or mastitis though underwire versions are readily available.
Open Tip bras have cups which loosely cover the breasts, but holes around the nipples. These kinds of bras do not give the underside of the breasts much support, but some versions do provide a shelf for the breast to rest upon. They are typically used by women as a statement of bold independence or for wearing in sexual situations.
Padded bras are simply bras with padding added inside the lining. They are designed to provide a fuller shape for small breasts and an alternative to bra stuffing, a practice among preteen and teen girls in which tissues, cotton balls, or socks are placed inside a bra to simulate larger breasts. Unlike push-up bras, however, most padded bras support the breasts but do not significantly lift them.
Push-up bras, are structured so that the breasts are lifted and the cleavage emphasised. The best known brand of push up bra is the Wonderbra. Many push-up bras contain padding, typically made of foam or rubber, but some contain pads filled with water, an oil/water mixture, or gel.
Shelf bras have a band, usually elastic, that goes across the entire front of the chest, beneath both breasts. These are often found built into camisoles. The term is also used interchangeably with built-in bra.
Sports bras or jogging bras are for women to wear during exercise. They are more sturdy in their construction than regular bras, and offer greater support for the chest, thus increasing comfort and reducing the chance of damage to the ligaments of the chest during high impact exercises such as jogging. They are usually made of a stretchable, absorbant fabric such as Lycra, and may be designed to draw perspiration away from the skin to reduce irritation. Many women, particularly those with large breasts, find sports bras essential for exercise, as breasts bouncing can cause pain and discomfort, as well as embarrassment. Some sports bras are meant to be worn as outerwear.
Strapless bras, with no shoulder straps are designed for wearing with clothes that reveal the shoulders, such as halter tops. Convertible bras have straps which may be detached and rearranged in different ways depending on the outfit. Alternatives to regular straps for strapless bras are beaded bra straps or clear plastic bra straps, that provide support and style.
T-shirt bras are designed without raised seams, so that a tight t-shirt may be worn without the bra being visible. These bras are the perfect selection for any knit fabrics that are clingy, since there are no visible bra lines under the garment when properly sized and worn.
Training bras are for girls who have begun to develop breasts but have yet to develop enough to allow for a standard sized bra to fit properly. They are of simple construction and offer little, if any, support. They were created to recognize developing tissue as sensitive and, at times, in need of coverage in order to maintain comfort.
Underwire bras are designed to provide extra support through the use of a "wire" under the breasts which push against the body and provide structural support to the breasts. The "wire" can be metal, plastic, or some composite material. Early undewire bras used very stiff and rigid wires, but newer technology now allows light flexible underwires that provide excellent support. | 
