What's the difference between that and being biloveual?
The prefix "bi" means two which would mean that, technically, "biloveual" could only mean you're attracted to plain cis boys and girls. While panloveual would also include transgender people, people with unusual combinations of genitals (like, people with boobs and a snake, or something. not super common in real life stuff), and whatever else. "Pan" means "all."
In practice, though, most people just use "biloveual" even when it includes those other people.