A censor takes out things that are objectionable or inappropriate, like the censors at the TV networks bleeping out all the bad words in a show.
To put it simply, a censor judges. Originating in the 1530’s, a censor was originally a Roman magistrate who took censuses and oversaw public morals. Censors today are hired by TV stations, publishers and the government to examine books, films and other material and strip out or flag all the amoral, offensive or otherwise bad stuff. Thankfully, in the U.S. free speech usually wins out over censorship.