So, you know that feeling when you are really happy and excited, and you just want to tell everyone about it? That's kind of like "exclaiming".
"Exclaiming" means to yell or say something loudly because you are feeling strong emotions like joy, surprise, anger, or fear. It's like when you see a really cool toy and say "Wow!" really loudly.
When someone "exclaims", they are trying to make sure everyone around them knows how they are feeling. It's like putting an exclamation point at the end of a sentence - it makes it clear that you are really trying to get your message across.