Okay kiddo, imagine you are going on a trip and you want to pack all your toys, clothes and snacks in a big bag. Now, think about a big ship carrying lots and lots of bags like yours, but instead of toys and clothes, they have all kinds of things like food, toys, electronics, and sometimes even dangerous things like guns or explosives.
Now, everyone wants to make sure that these bags (also known as cargo) don't have dangerous things in them, so they use special machines to scan them. These machines have big eyes that can see inside the bags and check if there is anything in there that could be harmful.
Sometimes, if they see something suspicious, they will ask the people who packed the bags to open them up and check inside. This is like when mommy or daddy ask you to show them what's inside your backpack when you come back from school, to make sure you didn't bring anything dangerous or harmful.
The people who work with these special machines are very smart and trained, so they know what to look for and what kind of things are not allowed on the ships. They work hard to make sure that all the cargo that goes on the ships is safe and won't cause any harm to anyone.
So, cargo scanning is just like having a big eye that looks inside bags to make sure they don't have anything harmful or dangerous in them. It helps keep everyone safe and make sure that things are delivered from one place to another without any problems.