A man is a male human, in contrast to an adult female, who is a woman.
The term man (irregular plural: men) is usually used for an adult, with the term boy being the usual term for a male child or adolescent (sometimes also applied to adult men). However, the term is also used for a male human regardless of age, sometimes even extended to more primitive humanoids then the present species Homo sapiens sapiens, as in apeman.
A boy is a male human child. For many, the word man implies a certain degree of maturity and responsibility that young men in particular often feel unprepared for; yet they may also feel too old to be called a boy. For this reason, many avoid using either man or boy to describe a young man and prefer colloquial terms such as bloke, lad, chap, fellow, guy or the like.
In terms of sex, men have various sexual characteristics that differentiate them from women. Just as in women, the sex organs of a man are part of the reproductive system, consisting of the penis, testicles, vas deferens and other sperm cords, and the prostate gland. The male reproductive system is oriented around producing and ejaculating semen which carries sperm and thus genetic information. Since sperm that enters a woman's uterus and then fallopian tubes goes on to fertilize an egg which develops into a fetus or child, the male reproductive system plays no necessary role during the gestation. The concept of fatherhood and family exists in every human society.
The secondary sex characteristics, such as body hair and muscle growth, are involved in attracting a mate or in defeating rivals. But these secondary traits are also often related to reproduction in some manner. In contrast to women, men have sex organs that are mostly considered to be external, although many parts of the male reproductive system are internal as well (such as the prostate). The study of male reproduction and associated organs is called andrology. Most, but not all, men have the karyotype 46/XY.
In general, men suffer from many of the same illnesses as women. However, there are some sex-related illnesses that occur only, or more frequently, in men. For example, autism and color blindness are more common in men than women. As well, some age-related disorders such as Alzheimer's disease appear to be more common among men, though whether this is due to a genuinely higher incidence or because men have lower life expectancies than women is uncertain.
Furthermore, in terms of sociology, men are more likely to be victims of conflicts, such as social isolation, alcoholism, violence and accidents, especially if the larger society is failing. This has lead to major changes in population structure in e.g. Russia, where men have a markedly lower life expectancy than women. When it comes to macrosecurity conflicts, men are often the ones fighting wars, and many genocides target only men.
Biological factors are usually not the sole determinants of whether a person considers themselves a man or is considered a man or not. For example, several men have been born without a typical male physiology (estimates range between one in 2,000 and one in 100,000), or some individuals with XY chromosomes can have an hormonal or genetic difference (such as androgen insensitivity syndrome), or another intersex condition; some of those intersex people, and others, who have had a sex assigned at birth seek reassignment later in their lives. (See also gender identity, gender role and transman.)
Additionally, 20% of males, particularly in the U.S., the Philippines, and South Korea, as well as Jews and Muslims from all countries, have experienced circumcision, a process of altering the penis from its natural state by removing the foreskin.
Some of these differences have been supported by scientific research; others have not. All should be considered broad generalizations, subject to the enormous variations among actual men and women.
A number of the above stereotypes were not perceived in the same way as today (i.e., their applications to particular aspects and spheres of life, such as work vs. home) until the 19th century, beginning with industrialization.
In terms of outward appearance, few men in Western cultures wear cosmetics or clothing generally associated with female gender roles. (Doing so is generally stigmatized and viewed as cross-dressing.)
Image:Soldier running in water.jpg|A U.S. Marine running through water Image:Bedouin man with Fez.jpg|A young Bedouin man
Man | পুরুষ | Home | Muž | Mand | Mann | Viro | Varón | Mies | Homme | Fear | Fear | איש | Uomo | 男性 | Homo | Man (geslacht) | Mężczyzna | homem | Мужчина | Omu | Man | Мушкарац | Man (kön) | ئەركەك | 男人 | Cha-po·