Stance is a synonym of Opinion. Bias is a type of Opinion. Racism is a type of Bias. 
Lake is related to Dam. Dam is a type of Structure. Structure is related to Bed. Bed is related to Mechanism. 
Stance <--Synonym--> Opinion <--IsA-- Bias <--IsA-- Racism 
Lake <--RelatedTo--> Dam --IsA--> Structure <--RelatedTo--> Bed <--RelatedTo--> Mechanism 