hdmi 2.1

And what if I buy a cable will it work

The Xbox Series X will come with a HDMI 2.1 cable,

But whether you use a HDMI 2.1 cable or not, the HDMI port on the TV needs to be HDMI 2.1 to achieve the 120hz refresh rates at 4K.

using a HDMI 2.1 cable on a TV port with HDMI 2.0 will still only limit the Xbox Series X to 60hz refresh rates.

[table][tr][td]Xbox Console HDMI Port[/td][td]HDMI Cable[/td][td]TV HDMI Port[/td][/tr][tr][td]Xbox Series X, HDMI 2.1[/td][td]HDMI 2.1[/td][td]HDMI 2.1 = 4K at 120hz[/td][/tr][tr][td]Xbox Series X, HDMI 2.1[/td][td]HDMI 2.0[/td][td]HDMI 2.1 = 4K at 60hz[/td][/tr][tr][td]Xbox Series X, HDMI 2.1[/td][td]HDMI 2.1[/td][td]HDMI 2.0 = 4K at 60hz[/td][/tr][/table]

but if the video feed is not going though a HDMI 2.1 port, the signal / bandwidth to the TV is limited by the HDMI port the it uses, be it a straight connection or some sort a splitter,

4K 120hz requires a HDMI 2.1 port, no HDMI 2.1 ports, no 120hz at 4K

Yes i have checked it out and the tv has HDMI 2.1 support and the hdmi cable has hdmi 2.1 support.

Thank you again, last question, will the xbox series X be able to support 144hz for monitors?

No, they will be capable of 120hz over HDMI 2.1 if you have a monitor with HDMI 2.1,

But, as of yet, there are no gaming monitor with HDMI 2.1,

The first gaming monitors to have HDMI 2.1 wont be available until the end of this year to early 2021.

The monitor is a 1440 144hz Monitor with HDMI 2.1 which is compatible for 1440p 144hz which is the Native resolution.

Your Monitor only uses HDMI 2.0,

There are no Monitor's available as of yet that supports HDMI 2.1,

The very first Monitor to support HDMI 2.1 ( The World's First Monitor to have HDMI 2.1 ) won't be released until the end of December if it doesn't get delayed and that's a 4K 144hz Monitor.