The difference between bias and stereotype is that a bias is a personal preference, like or dislike, especially when the tendency interferes with the ability to be impartial, unprejudiced, or objective. On the other hand, a stereotype is a preconceived idea that attributes certain characteristics (in general) to all the members of class or set.
If you think that all Asians are smart, or white men can't dance, that is a stereotype. But if you hire an Asian for a job that also has an equally qualified black applicant because you think blacks are not as smart as Asians, you are biased.
"Bias vs Stereotype." Diffen.com. Diffen LLC, n.d. Web. 31 Oct 2014. < http://www.diffen.com/difference/Bias_vs_Stereotype >