Bias is a one-sided preference for a particular view or perception. It is oftentimes considered synonym with prejudice ( http://en.wikipedia.org/wiki/Bias ), especially when the particular preference is not based on facts.
A cognitive bias is the human tendency to make systematic decisions in certain circumstances based on cognitive factors rather than evidence. ( http://en.wikipedia.org/wiki/Bias , retrieved 2013-01-17).
In the ux-field, bias is of significance when influencing or analysing user-behaviour and habits.
