Move all files from current directory to parent directory

mv * .[^.]* ..

Explanation: the mv command moves files and directories. The last argument to mv is the target (in this case the directory one step “up” in the tree, ..). The arguments before that are the source files and directories. The asterisk * is a wildcard which matches all files which do not start with a dot. Files that start with a dot (dotfiles) are “hidden”. They are matched using the pattern .[^.]*