Genderqueer means they don't identify as entirely male or female. It's based on the concept that gender is a spectrum, not a binary system. Genderfluid means they vary from day to day across the gender spectrum and some days identify more or less than one end. Pansexual means to be attracted to people of all gender identities, meaning male, female, transmale, transfemale, and genderfluid/non-binary. Most people are straight, gay, or bi, but pan includes trans people because they may have non-confoming genitals that a straight or gay person wouldn't be attracted to. While I personally believe there is validity in some of this, fats have taken to it because it's new, different, and gets them attention.