Okay so Omegaverse is an AU alternate universe Where, in most cases, a phenomenon happens that changed human dna/people evolved with an extra piece of dna that gave them a secondary gender. Well known as Alpha, Beta and Omega, along with sub categories of dominant and recessive, Alphas and omegas are less common compared to betas, the sub categories being even rarer. This phenomenon presents itself in the way of pheromones, a scent in simpler terms, only Alphas and omegas have this/can smell it. Betas are usually just normal people.
Pheromones in most stories are used as an identifier, kinda like a finger print, each smell is unique and have 2 main functions. For alphas it’s typically used to assert dominance , and for omegas while not limited to them it’s used to arose people, in some cases sway emotions. When someone is over powered by certain pheromones it’ll instill either great fear/submission in a person or the need to procreate.
In some stories people are just born this way, most times determined by family genes, or they are betas till puberty hits.
Alphas for the most part take on the dominant role, they are the leaders, athletes, celebrities, etc. there are however stories that play on this aspect and switch the roles completely, making them nothing more then instinct/sex driven slaves for reproduction and entertainment purposes. No matter their sex male or female, an alpha is able to impregnate anyone excluding betas and have a high fertility, especially around their rut a time of the month where their sex drive is high and their pheromones are ridiculously strong, in some cases they lose reasoning and seek out omegas to impregnate
Dominant alphas, are basically just ‘elites’ in every aspect and Recessive alphas are closer to betas, having weaker pheromones and irregular ruts, if any at all. and sometimes seen as inferior.
Omegas for the most part take on the submissive role, in a lot of stories societies view them as one of 3 things or all of these things 1. corporal burdens, they do not wish to even think about wasting medical studies on to provide medicine to help with things like their pheromones and heats i’ll explain that later 2. stay at home moms, their job is in the kitchen cooking and making children for their alphas or 3. sex objects, they have no bodily rights and are just there to make an alpha’s night better, weather they actually want that or not. this aspect is of course played with in a lot of stories, where sometimes they are set as equal if not above alphas, or use their body to reach the top. No matter their sex male or female omegas can get pregnant, and have high fertility. Especially during their heat that comes every months,lasting 2-4 days, where their instinct to reproduce are heighten and they lose reasoning, desiring any alpha that would impregnate them.
Dominant omegas are the peak omega, in beauty, brains and pheromones which they can sometimes use to persuade alphas, or even betas emotions as the pheromones are strong enough that even a beta can smell it and recessive omegas are closer to betas, having weak pheromones and irregular heat cycles. and depending on bodily autonomy have lesser chance of birthing children
Lastly is bonding/marking In most stories there is a spot on the nap of the neck where pheromones are secreted the most, that’s a sensitive spot that when a alpha bites as typically they are the only ones that can bond multiple omegas to them, but omegas can only have one alpha on the spot, hard enough to draw blood, some chemical magic happens and the omega is now bonded to the alpha. In some stories their pheromones will merge, creating a unique scent that says they belong to each other, usual if the bond is mutual. Or in some stories it’s just this permanent scar on the neck, but in every case the receiver of that mark is unable to have sex with or even reproduce with anyone but the person they are bond to.
There’s also a cute lil magical phenomenon called fated mates/pair where an alpha and omega are just “Destined” to be together, some explain through science “their phenomenons match up perfectly with the other, linking them together” , others use things like the red string of fate, either way I find it very cute, it’s usually terribly rare case in any story it’s used in.