What is Polyamory?
Strictly translated, polyamory means "many loves"; a polyamorous person is someone who loves more than one significant other, spouse, boy/girlfriend, or lover. It's not about swinging, open marriage or sex in general; however, it does include open dyads/couples, intimate tribes/clans/networks, group relationships/marriages, triads, quads, septets...
If you can think of a committed loving relationship that includes more than one person, then you've got a decent grasp of the concept. It's not a casual escapade; the work needed to be in an honest, growing, healthy relationship rises exponentially when you increase to more than a standard couple. Thus, poly people are often very seriously committed to personal honesty, relationship integrity, and trust.
Of course, the benefits also grow exponentially. Love is infinite. Act like it.