For example if I search for "python books" I get results about books teaching the programming language. I'm a programmer and this makes sense in that it is both 'relevant' and 'accurate'.
If my girlfriend does the same search she gets books about snakes. She is a biologist so it is again both 'accurate' and 'relevant'.
The problem arrises if she gets results about programming because she does not know or care about it. It is technically 'accurate' but now the product is useless to her.
Look at the Wikipedia article for "python". There are too many uses for the word.