Pansexuals have the capability of attraction to others regardless of their gender identity or biological sex. A pansexual could be open to someone who is male, female, transgender, intersex, or agendered/genderqueer.
Pansexual identified people have the physical/emotional/spiritual capability of falling in love or being with someone regardless of their gender. This doesn’t mean they like everyone, and some Pansexuals do have physical preferences. The identity is used merely to express the openness and fluidity to people of all genders.
Pan means “all” while Poly means “many” and so there are some similar overlaps, a Polysexual may be attracted to some gender variant people but not have the capability or desire to be with some others. Pansexuals are open to any person regardless of their gender or sex.
Pansexuality is not to be confused with Bisexuality in which “Bi” denotes two genders (male & female) and “Pan” being “all” is open to people who fall at all points or even outside of the gender continuum.