Soundness

Imagine you're playing a game of matching shapes with your friend. You have a blue circle and your friend has a green square. You both agree that the only way to win is to match the shapes and colors correctly. So you try to match your blue circle with your friend's circle. But then your friend says, "No, we need to match colors too! My green square won't match with your blue circle."

That's kind of like soundness. Soundness is the idea that the rules you agree on are the right ones. Just like how you and your friend agree that matching colors is important, people who use computer programs need to agree on the rules or assumptions that the programs use. These rules help the programs work correctly and give the right answers.

Sometimes, people make mistakes or don't agree on the rules. That's like if you and your friend couldn't agree on the rules for the matching shapes game. If you both had different rules, you might end up with different answers and neither of you would know who won.

So soundness is important because it helps everyone agree on the same rules and get the same answers, just like how you and your friend agreed on matching shapes and colors correctly to win your game.