|This article needs additional citations for verification. (January 2011)|
A main difference between male briefs and female briefs is that male briefs are often designed with a seam or much larger pouch in the crotch area to accommodate a bulge. This is because men and boys have larger external genitals in comparison to women or girls, thus requiring more fabric in the crotch area. Male underpants also have a front opening for the penis to exit to facilitate urination. 
See swim briefs for the case of briefs as swimwear.
Briefs were first sold on January 19, 1935 by Coopers, Inc., in Chicago, Illinois. They dubbed the new undergarment the "Jockey" because it offered a similar degree of support as the jockstrap (one style of which is also called jock brief or support briefs). Thirty-thousand pairs were sold within three months of their introduction. In North America, "Jockey shorts" or "Jockeys" was an often used generic term for men's briefs. More recently, "tighty-whiteys" has become a commonly used nickname for briefs.  
In the UK, briefs were first sold in 1938. Soon, shops were selling 3,000 briefs per week. They were so popular that in 1948, every member of the British Olympic team was given a free pair of briefs.
In Britain, the term "jockeys" has not caught on and briefs are often referred to as "Y-fronts". The term derives from the genericized trademark "Y-Front", property of Jockey International. It in turn derives from the inverted Y-shape formed by the seams at the front of the underpants. The colloquialism is used even when the fly opening may differ in style, and not actually form the shape of the inverted letter "Y" fly on Coopers Jockey brand briefs.
In Australia, briefs are referred to as "jocks" but should not be confused with jockstraps (more specifically used by athletes) which expose the buttocks. Australians generally use the word briefs to refer to the bikini-style underwear for men, which do not have the Y-front opening.
Since the ending of the 20th century, a hybrid called boxer briefs has become popular. Like boxers, they have short legs, but like briefs, they are made of elastic, snug-fitting material. A shorter version of boxer briefs are called trunks.
Briefs often feature a fly - a covered opening on the front of the garment which allows for convenience at urinals. There are several different fly designs in common use, including but not limited to the standard vertical fly, the horizontal fly, and the y-front fly. The use of a fly is optional, and many styles do not utilize a fly at all.
Traditional size briefs for both sexes cover the upper part of the thigh and extend upward up to (or cover, depending on the design) the navel. This style is often referred to as "full rise" or "full cut". There are also "low rise" and "mid rise" styles whose measurements vary between manufacturers.
In the case of men's underwear, briefs, unlike boxer shorts, hold the wearer's genitals in a relatively fixed position, which make briefs a popular underwear choice for men who are participating in athletic activities or who feel they need more support than loose-fitting underwear can provide. In addition, boxers often ride up the body when the wearer is running.
Briefs also refers to a style of women's and girls' panties that is typically cut with a high waist to provide full coverage of the hips and buttocks. A control brief is a kind of high-waisted panty girdle. French-cut or high-cut briefs expose more of the front part of the thigh, while boy briefs have short legs, similar to men's boxer briefs, often combined with a lower waist.
Briefs is also the name given to costumed outerwear worn by female dancers and athletes in sports such as cheerleading, figure skating, and tennis. These briefs are typically worn under a short skirt; they may be attached to the skirt or dress body, or a separate garment ("cheer briefs").
Briefs and fertility
Tight briefs have been blamed for negatively affecting the semen analysis, since they may interfere with the cooling of the testes. However, not all research has come to the same conclusion. A study in the October 1998 Journal of Urology, for example, concluded that underwear type is unlikely to have a significant effect on male fertility.
Media related to Briefs at Wikimedia Commons
- New York Magazine - 29 Apr 1985 - Page 30
- MENS UNDERWEAR, JS Atlee - US Patent 3,517,666, 1970
- Jockey Singapore, Y-Front Fly
- WebMD, Boxers vs Briefs
- http://www.brucegilbertmd.com/uploads/assets//Journal_Articles/boxersvbriefs.pdf A critical analysis of the role of underwear type in male subfertility