I noticed that when I triple click (with mouse) to select text (or a command) from say a website, and then paste this into my terminal using Ctrl+Alt+v, then the command runs immediately (i.e. it automatically inputs Enter key), but if I select(with mouse) and copy the same command and use Ctrl+Alt+v to paste it into the terminal it does not auto-run the code but it rather just pastes it and awaits input from me before the code will run.
Which mechanism makes this so? Because I would rather first look at the command to be run before running it, but I noticed this will be done for me any time I use triple click to select a word.