Used to be men. Then, fairly recently, that stered to change ,so many people started to use the words waiter, waitress, fireman, or policewoman in english to show the gender of the person in the occupation, so as to make the meaning clearer, and allow for the social changes. Nowadays, however, many people prefer to use terms that are more generic, such as server, firefighter, or police officer, because many people wish men and women to be treated equally, even in terms of the words used to describe jobs.