Now, I don't want to start an argument in the comments, so this is just how I think of pan vs. Bi.

Bisexual: someone who feels attraction to more than one gender, but not all genders.

Pansexual: as I previously mentioned, feels attraction towards ALL genders. Sometimes considered gender blind

As you can see, bisexual is NOT the same as Pansexual, and BOTH are completely valid.

Hope this helped,

Now bye-

Cya soon!