Keyboard with WLAN- how does it work?

I'm looking for a functional old keyboard (because I love the sound) for my laptop.

I found it, but the buyer says that the keyboard works with Wi-Fi. Or is wireless, the battery has to be inserted and should work with Wi-Fi… Have I never heard of? Then how do I connect it to the laptop?

the buyer can unfortunately not help me.

I think the seller confuses Bluetooth with Wi-Fi.

He means I have never heard of Bluetooth Wi-Fi.

There are wireless keyboards, but they are not called WLAN, even if they radio on the same frequency.

There's a Wi-Fi symbol on the keyboard… That's why I'm confused

I thought so too, but there's a WLAN symbol on the keyboard itself.

Do you have a picture?