(Not sure if I put this in the right group, so I apologize if it's wrong) I saw someone on here mention something about a demisexual, but I was unsure about what it is. I began to think about all of the different kinds of sexualities that people identify with and googled something to try and help me understand. I found this chart on Google Images and had a few questions.

What if the difference between bisexual, pansexual, and polysexual? And what is the different between homosexual/gay/lesbian and queer? (Just to clarify I have nothing against anyone who identifies as anything, I have friends who are many sexualities (cliche to say, I know) I just want to know more about them).