Dumb question about lightning network

I’m a little confused about the lightning network. I watched a video about getting started they showed using an exchange to buy “lightning bitcoin”. I was previously under the impression that the lightning network was simply a network/2nd layer that batched btc transactions together to allow for higher transaction volume and lower fees. Sorry if I sound dumb I don’t know much about the lightning network yet. Could anyone explain what the video meant/ if buying “lightning bitcoin” is really necessary or if the LN works as I described?

Edit: Here’s the video I watched. He mentions “lightning bitcoin” around the 10 min mark.