There are many types of underwear for men. Depending on what type of clothing a man wears, some underwear is more comfortable or efficient than others. Each type of underwear has its advantages and disadvantages, and is worn with different types of clothing in different environments. These are all factors when men choose what type of underwear to utilize.
Briefs are also known as "tighty-whities," as they are small and often white undergarments worn by a man around his waist, which holds the fabric close to his body. Briefs stay up with a piece of elastic around the top and pieces of elastic around each leg. Briefs come in more colors than just white, and are often worn because they prevent genitals from moving around too much (which can cause discomfort). This type of underwear keeps the testicles close to the man's body, which generates heat and can lower sperm count.
Boxers are basically shorts men wear under pants. Boxers allow a large amount of movement and more air flow to the crotch region. These shorts have an elastic band around the top, which fits snugly against a man's waistline while allowing the bottoms to hang loose and free. Boxers come in many different colors and designs, some with funny, suggestive sayings or logos on them. The downside of boxers is that they tend to bunch up within pants, which can be uncomfortable and require the need for constant adjustment. This is especially true with silk boxers, which tend to cling to a man's legs.
Combining the two classic forms of men's underwear into one was bound to happen someday and boxer briefs are the result. This type of underwear consists of shorts reaching the middle of the thigh on most men, with the top fitting snugly against the crotch and waist. Like briefs, there is elastic around the waist and the bottom of each leg. Boxer briefs provide the best of both worlds, as they don't ride up like boxers, yet provide more room than briefs themselves. However, like briefs, boxer briefs can become hot due to their close proximity to the body, and may play a factor in lowering sperm counts.