As nouns the difference between purser and steward
is that
purser is the person responsible for handling the accounts on a ship, or for dealing with the passengers on a ship or aircraft while
steward is a person who manages the property or affairs for another entity.
As a verb steward is
to act as the steward or caretaker of (something.
As a proper noun Steward is
{{surname|A=An English|from=occupations}}, a variant of Stewart.