So, imagine you and your friends are playing with toy soldiers and you have some rules to follow to make the game fair and fun. Well, countries have rules too, but they call them "conventions." One of these conventions is called "The Convention on Certain Conventional Weapons," and it's like a big rulebook for countries to follow when they are making weapons.
Now, "conventional weapons" means weapons that are not nuclear or chemical, so things like bombs, guns, and grenades. The convention wants to make sure that these weapons don't cause unnecessary harm to people and animals during wartime.
For example, one rule is that weapons shouldn't have parts that will stay in the ground or water when the battle is over. If that happens, it could hurt people and animals who come by later, like farmers or fishermen. The convention also doesn't want weapons to hurt people in a way that is too cruel or inhumane, so they have rules about things like using poison or using weapons that cause too much pain.
Overall, the Convention on Certain Conventional Weapons is like a big game rulebook for countries to follow, to make sure that weapons are not too destructive and that people and animals are not hurt in unnecessary ways during war.