Pansexuality is when there is a sexual, romantic, or just some emotional attraction towards persons of all genders. It doesn't matter if they're male or female. uvu
Actually, bisexual is one who is attracted to only male or female genders. The "bi" in bisexual means "two". Pansexual means all genders, ("pan" meaning "all", in case you haven't figured that out) which extends to transgender, androgynous, and many other sexual identifications besides just male and female. Some refer to pansexuality as being "gender blind" because one who is pansexual usually disregards gender as a reason for being attracted towards someone. Hope this cleared things up.