Sometimes, when you use your cell phone, you may notice that you have no signal and you cannot make any calls or send messages. This is called a "dead zone." It's like a place where your phone cannot talk to the towers that help it make calls and send messages.
Imagine you and your friend are playing a game of catch, but you both have to stand close to each other to throw the ball. When one of you moves too far away, you can't throw the ball to them anymore. This is kind of like what happens with your phone when you enter a dead zone - it's too far away from the towers it needs to talk to.
Dead zones can happen for a few reasons. Sometimes, the area you're in just doesn't have good coverage from cell towers. Other times, there might be something blocking the signal, like tall buildings, trees, or mountains. If you're inside a building or underground, the signal might not be strong enough to reach you.
When you're in a dead zone, your phone might try to keep searching for a signal, which can use up your battery pretty quickly. So, if you can't get a signal, it's best to wait until you move to a different area where you can get a good connection.