shorts

Shorts are a garment worn by both men and women over their pelvic area, circling the waist, and covering the upper 
part of the upper legs or more, sometimes extending as far as mid-calf, but not covering the entire length of the leg, 
either as outer or undergarment. They are called "shorts" because they are a shortened version of pants which cover the entire leg. 

Within the United States, historically, in the 19th and early 20th centuries, shorts were only worn by young boys until 
they reached a certain height or maturity. When they got older, they would receive their first pair of long trousers. 
This produced the perception that shorts were only for young boys. Because of this, men would not wear shorts to avoid looking immature.
Since about World War II, when soldiers often served in tropical locations, adult men have worn shorts more often,
but the perception of shorts only being for young boys took several decades to change and to some extent still exists. 

Today, shorts are worn by either sex in the United States, from birth through old age without any stigma attached. 
But in many countries there are few formal settings where wearing shorts would be acceptable, as they are considered casual wear. 
In many American offices, where there is an official casual dress standard, shorts are often specifically forbidden. Since the 1990s,
casual office dress has grown in many businesses to include dress shorts. Gym and jean shorts are often seen as too casual for office attire.

Styles
There are many styles of shorts:

Baggies: Loose fitting shorts which reach the knees. These were the standard shorts worn by English football teams before World War II

Bermuda shorts(also known as walking shorts or dress shorts): Knee-length shorts commonly worn in Bermuda as business attire,
or largely any style less than formal or black-tie. The style has also been adopted exclusively as a casual style in other locales.
Usually has pockets and waist loops for an optional belt.

Boxer shorts: Mainly used as male underwear. Some years ago, this term also related to a basic style male short. 

see lots more styles here: 

https://idkapparel.com