What does Plex DVR actually mean?

So, I just heard about Plex Pass and about the live TV and I’m sort of confused. I’ve been meaning to get rid of the traditional TV subscription that I’m paying monthly because I’m sick of my DTH operator and their services(I’ve already told them to terminate my service). So this really intrigues me.

I’ve recently bought a chromecast in order to somehow get rid of the Set-top Box system and simply use my internet for watching TV and movies. So far, I’ve only been able to watch my locally stored movies and stream videos from apps which are chromecast enabled.

My question is, if I get a Plex pass, would it just be as simple as downloading the plex app and stream live tv to my chromecast? Just like I do with my movies and locally stored videos and media. Or would I have to invest in more hardware? What is plex DVR? Is it a physical DVR from Plex?

https://support.plex.tv/articles/categories/plex-media-server/dvr-live-tv/

What I’m asking is, would it work if I don’t have a physical antenna or DVR setup? Would I be able to stream live TV to chromecast without having them and just having the Plex Pass?

I know that what I’m asking might sound a little stupid to anyone who knows about it, but I’m simply confused and so I need to get it cleared.

The Plex DVR is only able to record what is available on your location. Either over the air or un-encrypted per cable.
You won’t be getting any content from Plex directly, without having a tuner device at home.

Plex works with either your cable provider or antenna. What you are asking for is something like Sling TV or YouTube TV (and many other similar services).