F# is a Part of the sharp family or whatever you want to call it but any note with # is a sharp, A sharp is raising the notes pitch to make it higher where Bb stands for B flat, Flat meaning to lower the notes pitch.
F# Would be on one end and Bb would be on the other because of the note's octave
the notes shown in the picture are going up raising their volume in pitch making it either higher or lower due to the kind of note it could be.
I don't know if this makes any sense
The letters are A, C, E, and G. you can remember this by the acronym ‘All Cars Eat Gas’