How Does Lists Work?

If I Have A Variable… It’s A Text Variable, And I Wanna Remove Something From It And Put Something Else Instead, And There’s Other Variables That Takes A Data Inside Of it, So I Wanna Make Sure To Update The Variable Itself.

I Wanna Know How The ‘Make A List’ Block Work? Does It Save The Data Inside The Variable itself Or Take A Copy Of It Then Make It A List? As there’s No Output To Connect to a set variable block

A Zoomed

So I Wanna Know What Happens After That Action