Pansexuals and bisexuals

Ok, so before I ask, this post is to clarify a doubt I have and I was discussing it with friends but just one of them is bisexual.

Question: what’s the difference between bisexual and pansexual?

I see a lot of people saying it’s the same, I even have a bisexual friend saying it’s the same, but I see other people saying it’s completely different.

So, since I only have one bisexual friend and none pansexual, I figured I could ask here to get real answers from a variety of people.

Please, no judging one another, this is highly educational.