let me tell u with an example,i am assuming you are studying for ca.
in the road to become a ca what are your expenses ,your coaching expense and suppose your home to coaching travel expenses .
But when we look at it like what is direct expense whats indirect ,we would see that ur coaching and your travel expense is direct expense cause its used directly for purpose of ur studies
whats indirect expense then
your fooding expense,lodging expense,your institution(school) expense you get my point
so in sense of a company suppose for lays company direct expense is purchasing of potato,purchase of oil,the labour in making chips,like that.Indirect are the lighting expense of factory .