Ketchup and catsup are simply two different spellings for the same thing: a modern, Westernized version of a condiment that European traders were introduced to while visiting the Far East in the late 17th century.
ketchup 和 catsup 是同一事物的两种不同拼写: 17 世纪末欧洲商人在访问远东时被介绍给一种调味品的现西化版本。