Okay kiddo, have you ever watched TV and suddenly the picture disappears and you can't see your show anymore? That's kind of like a lost television broadcast.
When TV shows are made, they are sent out into the airwaves so that people can watch them at home on their TVs. But sometimes, for a lot of different reasons, the signal that sends the show to your TV gets lost.
It's like throwing a ball to your friend. Sometimes the ball goes straight to your friend and they catch it easily, but other times the ball gets lost and you have to go find it. The lost TV broadcast is kind of like the ball getting lost.
One reason a TV broadcast might get lost is if there's bad weather, like a storm. The signal that sends the TV show to your house doesn't work as well during heavy rain or snow, so your TV might turn off or show a "no signal" message.
Another reason is if the TV station has technical problems with their equipment. Just like the batteries in your toy might run out, the equipment at the TV station might stop working too. That means the TV show can't be sent out to people's homes properly.
Finally, sometimes TV broadcasts can get lost if they are too far away from your TV antenna. Just like you can't throw a ball too far and have your friend catch it, a TV signal can't travel too far either. That means if you live in a far-away place, like on a mountain or in the countryside, you might have trouble getting a good TV signal because you're farther away from the TV station.
So, that's a little bit about lost television broadcasts. Just like anything else, sometimes things don't work perfectly, but usually they're fixed pretty quickly so you can get back to watching your favorite shows.