Jeeves is mainly the servant to Bertie Wooster, a rich, foolish, foppish but good-hearted post-First World War bachelor (though in the style of the twenties), with whom he makes up one of the great comic duos of English literature. Jeeves uses his near-omniscience to get Bertie out of tricky situations, usually out of unsuitable engagements (to, for example, Madeline Bassett).
Jeeves is well-known for his convoluted speech and for quoting from, among other things, the plays of Shakespeare and famous Romantic Poets. He also has distinct opinions about certain items that Bertie adopts, such as a moustache, handkerchiefs with initials on, straw boater, an alpine hat etc. Should an item be disapproved by Jeeves it is certain that Bertie will dispose of it some way or another before the story is up.
The character's propensity for wisdom and knowledge is so well known that it inspired the search website Ask Jeeves.