Men as a collective term, encompasses beings of the human race in Tamrielic culture. Male humans, as a group, are referred to as "men" while female humans are "women". A combination of male and female persons are called "men".
Drastically different culturally and physiologically from Mer and Beastfolk, humans are genetically capable of interbreeding with the former, while rumors of interbreeding with the latter exist, but are unproven.
Humans come in an array of skin tones and pigments depending on race, with Nords and Bretons being the palest and Redguards being the darkest. Of the human race, there are four subraces currently existing on the Tamrielic continent. These include, Imperials, Nords, Bretons, and Redguards. The Nedes are an extinct human race from which most of these men sprang; the exception to this is the Redguard race.
Unlike Mer, there is no known continent or a region in Nirn Men originated from. There are no known elven records on this subject and men invented writing relatively late, meaning that there are no early records written anywhere.
Earliest records mentioning human races date mid-Merethic Era when Atmorans, a human race native to now frozen Atmora, began migrating to northern Tamriel, a region later named Skyrim. Most of the human races now inhabiting Tamriel are known to be their descendants.
However, when Atmorans began conquering Tamriel, they found Nede and Bretons, human races well assimilated in cultures dominated by elves. During the conquest of Tamriel by the people from Atmora humans already inhabited the whole continent, though mer were those who ruled it. They were probably the descendants of humans, who escaped Atmora, looking for a new, better life.
It also seems that some humans were aboriginal inhabitants of Tamriel known as Nedes and were native to Cyrodiil and Black Marsh. The Nedes and the Akaviri could well have been the same race, but the names was perhaps changed due to differing languages.[source?]
Some Imperial scholars believe that Men could have shared the elven homeland of Ehlnofay and have evolved from Aldmer like modern elven races. However, that theory is highly unlikely since men and mer have many differences.
However, the most plausible theory on the subject of the origin of the Human race was before the First Era on a continent called Akavir, outside Tamriel. The Humans were divided into two distinct groups, the Akaviri and the Tsaesci (serpent-like men). The lesser race, the Akaviri were enslaved by the Tsaesci and taught how to farm, fight, smith and serve. After a failed revolution by the Akaviri agains the Tsaesci, many did escape and to Tamriel to set up tribes and villages, free of the Tsaesci. This could be the source for the aboriginal tribes in Cyrodiil and Black Marsh , as well as Skyrim. Windhelm is the oldest city in Skyrim, and the oldest, fully-fledged human city in all of Tamriel.
The most significant difference among men and mer is their lifespan. Unlike the centuries-old elves, human races cannot live more than one hundred years naturally; most die when they turn sixty to eighty years old.
It is very easy to tell men from mer visually as men are more muscular than most elves and have fewer shades of skin color. Another easily noticeable feature of Elven kind is their pointy ears, which men do not have and the fact that most elves, even the women, stand at twelve inches or more over most men. Some exceptions to this rule are the Orsimer, whom are very different from other elven races. They resemble other beast-like races such as Goblins and the Bosmer (Wood Elves), who are shorter than most humans.
Another difference worth mentioning is that humans rely mostly on non-magical warfare, as they don't have the magical potency of elves. The only exception for this would be the mix of human and elven races - Bretons. Although magicka is used, in one form or another, by all races of Tamriel, direct magicka, i.e. casting spells of destruction or enchanting (etc.), is considered weak and/ or heretical by men.