Orchid2, 45

I'm new to all of this. I could use a lot of help understanding exactly what it entails. I'm very open minded and don't judge. Right now me and my boyfriend are in an open relationship, he has another girlfriend I am not seeing anyone else. He recently asked me if I would be willing to be in a poly relationship. As i dont really know what it is I told him id have to do my homework on it first. Please help. I have asked other places like craigs list but never got what I felt like was an honest answer. Please know I am very open minded, dont judge, I'm more curious then anything else. We have had treesums and enjoyed them quite a bit. Please help me understand.