A bomb is a really, really big and dangerous thing that can hurt or even kill people and cause a lot of damage to buildings and things around it. It's like a super powerful firecracker, but way more powerful!
You know how when you blow up a balloon and then let the air out really fast it makes a loud noise? Well, a bomb works kind of like that, but instead of air, it's filled with explosive materials that when ignited can cause a very powerful explosion.
People make bombs for different reasons, but mostly it's to hurt other people or to cause destruction. So, it's very important to stay away from anything that looks suspicious or out of place because it could be a bomb.
If you ever see something that looks like a bomb, the best thing to do is to stay away from it and tell an adult or call the police so they can come and make sure everyone is safe.