HEre image attached of one example. index.html and index.html~ appears everytime I finish editing the file. But it does not have any content and it does not go away unless I delete it, but, I am afraid of deleting the actual file.
index.html~ is meant to be a backup of the file.
When you edit a file with Gedit, Ubuntu saves the original as
filename~. The backup file is supposed to reflect what the original file looked like before it was edited.
It doesn't contain a whole backup history. It just keeps the last version of the file for you.