how to install steam in ubuntu 20.04 code example

Example 1: how to install steam on ubuntu

$ sudo apt update
$ sudo apt install steam
$ steam

Example 2: how to download steam on linux

Go to the steam store page, and find any game YOU want to play.
I'd sugest a free game like War thunder (just incase it doesn't work)
Make sure you're signed in and have an account
Press 'download' (or add to my library, and make sure it has the steam logo above to the right)
Press 'No, i need to download steam' once you've clicked it
Download the .deb file and launch it
login and download all the games you want
HAVE FUN!
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If that does work
sudo apt-get install steam
download steam and then find it.
Have fun

You can play Windows games on steam. Even if you're on linux. Go to settings (top left) and find 'steam play' and use the latest version of Proton.
Let porton download then restart steam
find a windows game and download it
press 'install' 
then to save hassle, go to 'Manage Downloads' and then click 'Play' button on the game (make sure it's NOT downloaded, but its currently downloading)
then it'll re-download using Proton