Standfirsts refer to an introductory or summary line or brief paragraph, located immediately above or below the headline, in isolation from the body of the article
The lead paragraph is the opening paragraph in a news story that summarizes the facts of the news story in order of most newsworthy to least newsworthy
The main features of news articles (headlines) are to provide a concise summary of the story, while standlines introduce and discuss/explain secondary details about the story