1 [uncountable and countable]
if you have a preference for something, you like it more than another thing and will choose it if you can [↪ prefer]:
Do you have a colour preference?
a cultural preference for boy babies
Parents may be able to express a preference as to the school their child will attend.
The amount of sugar you add will depend on personal preference.
Many elderly people expressed a strong preference to live in their own homes.
in preference to something (=rather than something)
Use clear English in preference to technical language.
2 [uncountable and countable]
when someone is treated more favourably than other people, often when he or she has been treated unfairly in the past:
Racial preferences are a way to make up for years of discrimination against minorities.
give/show preference (to somebody)
In allocating housing, preference is given to families with young children.
someone's sexual preference is whether they want to have sex with men or women