Given a category and a set of five words, find the word from the set that does not belong (i.e. is the least relevant) with the other words in the category. Words are separated by commas.

Category: type of rigidity 
Words: unbending, unyielding, inflexible, firm, streamline
streamline

Category: aesthetic characteristic 
Words: luke, fair, variety, tone, well
luke

Category: computers 
Words: keys, file, download, folder, type

type