What is tape delay?

It seems like a pretty stupid question to ask. I've noticed that on shows in America, for e.g. TODAY, their programme is tape delayed. Which makes me think about whether I know what tape delay is or not?! So any breaking news that would occur would be broadcast an hour later in another region, so them people would find out the news an hour later then others?

Someone please elaborate with what tape delay is because I don't think I've got the right description for what it is.

Whenever I've watched Today, the main reason it's 'delayed' is because of the time differences between ET and PT. This gives them the opportunity to edit out any problems that happen on the 'live' ET broadcast. I've noticed this with other live shows such as American Idol as they usually give the times its on for ET and CT and for the West Coast it's delayed.

There's a good wiki article here...

Broadcast Delay

Which then makes me be confused over what would happen on newscasts if there is breaking news? The people on the west coast would receive news that was announced hours ago right?

American Idol does that too?! So the people on the west again would find out the winner of the show a few hours after viewers on the east find out?! In this day and age of social media too wouldn't you find out there before the show has even began?

Even Dancing with the Stars is delayed for the West Coast, but I'm pretty certain that if anything of major importance, the West coast affiliates would break out of their schedules and take the breaking news.

For breaking news, they go live in all time zones with a 'Special Report' and ditch the scheduled show. Presumably that is why they are so common as opposed to our breaking news flash during an update.

Scottish television, and a few other itv stations, used to tape delay stuff. Agenda is one modern e.g.

There's some info here about a system the BBC VT department lashed up in the 60s, a different type of tape delay to allow profanity etc to be dumped rather than being broadcast

http://www.vtoldboys.com/hotline.htm

Here's an example from NBC where during the Nightly News ET, they break into the other time zones when breaking news hits
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