Most people know what a sound bite is from the TV news. It is the short video or audio clip the news media runs, that purports to summarize or characterize a particular opinion, position, or solution to a known problem. It is usually a short catchy comment from some political leader or other well known celebrity. One of the most famous sound bites in recent history was President John F. Kennedy's statement: "Ask not what your country can do for you; ask what you can do for your country." Another even more famous one is the defining sound bite of the Socialist movement: "From each according to their ability, to each according to their needs."
There are many sound bites out there that are interesting only in a general way. One of the more famous of this sort is Neil Armstrong's "That is one small step for man, one giant leap for mankind." These just capture a famous situation without suggesting any hidden agendas. Famous sound bites, are memorable sentences or phrases that stay with us and help define an event, an issue, or even a period in history. The more interesting ones mask with their pithy brevity, a whole host of hidden issues.
In journalism, sound bites are used to catch the attention of the audience, and summarize or characterize the story in brief, avoiding the need to provide the kind of details that an audience will never have the patience to hear. Media audiences have a notoriously short attention span.
In both print and broadcast journalism, sound bites are conventionally accompanied with commentary from the journalist to create the news story. A balanced news story should contain sound bites representing both sides of the debate. But the more common technique these days, however, is biased reporting. A short catchy snippet is selected for its sensational character, and is used to promote the point of view of one individual or group over another.