=IF(AND($F11="",$G11=""),"",IF(AND($F11="?",$G11=" ?"),"",IF(AND($F11=0,$G11=0),0,IF(OR($F110,$G110 ),(E11*F11)+(E11*G11/2)))))

I know these are multiple IF statements above, but I cant figure out what
the "" means?? eg. F11="". Does it mean if cell is blank then the cell with
this formula is blank ?

What about the "? " eg. F11="?". Does it mean if cell has any text in it
the the cell with this formula is blank ?

Thank for any feed back!

Brian