There could be many things: - One person is more reliable than the other - One person does more than bare minimum (you can love it or hate it but employers do

There could be many things: - One person is more reliable than the other - One person does more than bare minimum (you can love it or hate it but employers do care and pay attention) - One person solves more problems than others - One person owns more and complains less Lot of things that can make one person different than another even though they both may have the same job titles and responsibilities on paper.