Immutability is when something can’t be changed or edited.
Anything that has already been done are irreversible and can’t be changed.
Example: You’ve got a cheeky Tesco’s meal deal, you have just opened the sandwich wrapper, now you can’t close it back up, it’s irreversible and cannot be changed, and now you can’t eat the sandwich either nor remove it from the package.
So you cannot edit it, it’s impossible, sorry :(.