From Wikipedia: Polyamory (from Greek ???? [poly, meaning many or several] and Latin amor [literally "love"]) is the desire, practice, or acceptance of having more than one loving, intimate relationship at a time with the full knowledge and consent of everyone involved.
Whatever you call it, they all mean more or less the same thing. To understand the basics of this we have to understand our basic genetic makeup. Think of most mammals on this planet, they have some sort of signal that the female is ready to reproduce. These can be from there rears becoming red and engorged, to emitting pheromones into the air. We as humans do not do this, if fact the times when a human female is ready to reproduce is hidden even from her. To me this screams that we are to have sex as often as possible.
Add in the very disturbing things that happen when we don't add new genes into the pool. New genetic material must be added on a regular bases. We are made to spread out genetic material around, it's simple science. This added with the lack of a signal of a reproductive period lead me to believe that we as a race are meant to have lots of sex with many partners.
Ok logical science over, time for emotional...
To the shock of some, a poly relationship is not just about sex, or sex with someone/s outside of your marriage (at least not for all). Sex outside of your relationship for just the sake of sex is really just swinging, and that's another blog for another time. Poly is more about companionship, caring, and increasing the chances that someone's always going to be there for you.
Part if it is just pure numbers. If you have 2 lovers then the likely hood that someone that loves you will be available when you need them is doubled. This also goes for everything in a relationship, from the companionship, sex, and time. This works for those that have two lovers as well as the ones that share a lover. The example above shows how having two lovers can help make sure someone is always there for you. The other side of this coin is someone that you love, but due to jobs, family, or life you just can be there for all the time you don't have to be.
The other part is, and let's face it, some of us either need more attention than one person can give or have more energy than one person can take. We have all known people that are very very needy, well what better way to satisfy those needs then to double the people that you get that attention from.
Some poly groups all live together, or all live separately, or even with one couple living together and have the outside part comes and goes. Some are great distances apart and only see each other every few months, or they might even all live in the same apartment complex. Just like any other kink in life this is just a few examples of how poly works for some, but there as many flavors of poly as there are people practicing it.
I hope that this explains some of the basic workings of poly, both from emotional and logical stand points. As always I welcome comments and other views that I may have missed. Also, if you have any questions about this or any other subjects please send me a message here or at havenSOV@Gmail.com.
Later and keep it spicy!
-Haven De Lancret