Pansexuality, also abbreviated as pan, is a sexual orientation encompassing attraction to multiple genders, with the attraction being physical, romantic, and/or emotional.
Someone who is pansexual may feel that gender does not matter or instead feel it is a factor in the way that they feel attraction. Some pansexuals are attracted to different genders in different ways, or they are more attracted to particular genders.
Panromantic is a term used to describe people who are capable of feeling a romantic attraction toward people regardless of their sex or gender identity (the sexual equivalent of this is pansexual). Someone who is Panromantic may or may not experience sexual attraction for the genders that they are romantically interested in.
Because romantic and sexual attraction are not necessarily correlated, it is not necessary for someone to be pansexual in order to be panromantic and vice versa.
Other Definitions
Pansexuality is often seen as a part of the bisexual umbrella—anyone who is attracted to more than one gender.
However, Pansexual and Bisexual have nuanced differences that are frequently debated. Which label a person uses is ultimately a matter of personal preference.