this is done so that if we want to reinstall the same package on a photo, the settings we would have made are preserved. sudo apt get remove kile: this command deletes a package installed on our computer but keeps all the configuration files of the package.that is, the packages that were downloaded but never installed or the dependencies that were left in the cache after a new package was installed. sudo apt get clean: this command deletes all packages that are in the computer's cache.by including the name of the package at the end of the command, we can filter for results that contain only that string. dpkg l kile: with this command we list all the packages installed on our computer.