Dear @01101111 Thank you ver much for your expaining of rm command with the -rf option and also thank you fpr rm(1) - Linux man page which I read now and saved it in my tutorial folder.
In this connection I must add that the command rm -rf was issued by me following a guide in the link https://www.pcsuggest.com/install-wine-ubuntu/ . I am quoting its lines :
Extra - Uninstall Wine
If you think wine is no more useful, and want to uninstall, then it’s here.
Again We’ll use the apt command to uninstall wine from Ubuntu. Simply run the command below.
sudo apt-get purge wine wine-* sudo apt-get autoremove --purge
Finally remove the directory containing all run time data generated by wine.
rm -rf ~/.wine/ rm -rf ~/.local/share/applications/wine*
However, it is true that I have used blindly without knowing the implications.
Thank you again for all of you helping me in knowing a very basic problem.
I must thank @abhishek for his posts which helped me to learn the use of terminal in possible cases specially to install and uninstall a package and doing some basic works. I share this computer with my daughter and can use only when she is in her office. She was a window 10 lover but I have installed LM in this computer and she now asks me to find out packages similar to that of Windows she was using. I have done that and made her satisfied that almost all works can be done by Linux. I am closing this thread as solved so that I can start a new thread as I have so many things to know.