Short answers, pulled from the story.
Ivy Lee, known as the father of modern public relations, issued the first press release in October 1906. It documented a railroad accident involving the Pennsylvania Railroad near Atlantic City, New Jersey, which killed fifty people. The New York Times published his exact statement.
A press release traditionally contains nine structural elements: a letterhead or logo, media contact information, a headline of one to six words, a dek (sub-headline), a dateline with the release date and originating city, an introduction, a body, a boilerplate, and a close. In North America, the close is marked by the symbol "-30-" or "###".
A press release body typically runs four to five paragraphs with a word count of 400 to 500 words. The full document can range from 300 to 800 words depending on the subject.
A press release embargo is a request that news organizations withhold a story until a specified date or time. It is not legally binding unless a journalist has signed a non-disclosure agreement. Violating an embargo can damage a journalist's professional reputation and result in a news organization being blacklisted by the issuing party.
A video news release (VNR) is a pre-taped video program or clip distributed by public relations firms so that television stations can air it without modification. Full productions can cost tens of thousands or even hundreds of thousands of dollars. VNRs can also be formatted as TV news broadcasts or produced specifically for web distribution.
A communique is a specific type of press release issued by a public agency, typically after a high-level meeting of international leaders. It takes the form of a brief report or statement, distinguishing it from the broader category of press releases used by companies, political campaigns, and other organizations.