Okay, so you know how firecrackers make a loud noise and explode into different colors in the sky? Nuclear weapons are sort of like firecrackers, but way bigger and more dangerous.
The United Kingdom, which is a country across the ocean, has these nuclear weapons. They keep them to protect themselves from other countries that might want to hurt them.
The nuclear weapons work by splitting tiny particles called atoms. When you split atoms, a lot of energy gets released, kind of like when you pop a balloon and the air rushes out. This energy creates a giant explosion that can damage buildings and hurt people.
The United Kingdom has submarines that can launch these nuclear weapons. The submarines have special rooms where the weapons are kept safe until they are ready to be used. The people who operate these submarines are very well-trained and have to follow strict rules to make sure they don't accidentally use the nuclear weapons.
Using a nuclear weapon is a really big deal and can cause a lot of damage, so it's something that should only be done in extreme situations when there's no other option.