The practice of examining books, films, news, letters or online posts and removing or blocking the parts that someone in power does not want people to see. It covers both the act and the whole system: a government department, a set of rules, an unwritten habit of silence. Two things are worth noticing. First, English speakers stretch the word — a company deleting complaints from its own page gets called censorship by angry customers, even though no government is involved, and people argue about whether that counts. Second, it is not always about politics: film ratings, cutting swear words out of TV, a parent deciding what a child may read — all get called censorship, sometimes seriously and sometimes as a joke. The word is nearly always used by the person who objects; the people doing it prefer words like "guidance", "review", or "protecting the public". A related idea is self-censorship, when nobody stops you but you stop yourself because you know what would happen.