You can install Notepad++ on Linux using an unofficial Snap package with the command "sudo snap install notepad-plus-plus".
You might want to open two files in two separate windows to compare them. Also, if you want to edit two files simultaneously, you need to open them separately. That is why you can change Notepad ...
Those of us ancient enough to remember the time, or even having grown up during the heyday of the 8-bit home computer, may ...