Mmm... okay. It's a thing you can talk into that lets you talk to someone far away in real time. You hold it up to your ear like this [ demonstrates! ] to hear what they're saying, and there's a microphone down at the bottom that you talk into so they can hear you.
And then this is like, a way more advanced version of that.
Uh... well, the old ones used cables, similar to telegrams. But most phones are wireless now, so they just transmit things through, like, waves in the air or something, I think...?