I want to get either the PS5 or Xbox Series x. I only have a normal Full HD television, can I connect it to it and use it?
Of course you can. Higher resolutions are not required.
Yes, of course you can also use the console on a FullHD television.
I can recommend the Series s if you want to upgrade to 4K rather the Series x
So the Playstation 5 and Xbox Series S are perfect 1080p consoles.
However, if you want to switch to a 4K 2160p television in the future, you should consider buying the Xbox Series X, which creates native 4K (2160p) at a refresh rate of up to 120fps.
I'm a layman [= not an expert on the subject] but I think that almost any television set with a resolution of 1080p [Full High Definition for short FHD] is sufficient - unless you want the best possible picture, which is then probably a bit pimped up or upscaled.
My 4k TV is a bit older and I think it has an HDMI 2.0 connection. As I understand it, both consoles have an HDMI 2.1 connection and to get a 4k picture you would also have to have a TV or monitor with HDMI 2.1. It would be a shame if I can't get a 4k picture on my 4k television just because the connection is not the right one = D
You can also get a 4k picture via HDMI 2.0. The One X already offered that.
With HDMI 2.1, a combination of 4K and 120 FPS or even 8k is theoretically possible thanks to the higher transmission rate.
So no problem with your TV or a Series X or PS5.
Valhalla, Horizon 4 or Gears 5 run with native 4k at 60 FPS on the Series X.
And you can see and feel the difference on a UHD TV.