Valet: A valet is a personal servant, traditional responsible for a gentlemen and his dress. Today a valet might be any personal servant, as in valet parking. Valet is etymologically relate to vassal.
Butler: food, servants.
Valet: clothes, gentlemen.
'Jeeves was Bertie Wooster's gentleman's personal gentleman,' said Richard at his most pompous, straying dangerously where angels might fear to tread. 'A valet, not a butler.'
'But Bertie said Jeeves could buttle with the best of them.'