If the -r option is not used when attempting to copy a directory, the command will typically fail with an error message indicating that the target is a directory. For example, using cp without -r will not allow you to copy a directory and its contents, as the command expects a file rather than a directory.
For instance:
cp source_directory destination_directoryThis command would result in an error like:
cp: omitting directory 'source_directory'In summary, without the -r option, you cannot copy directories; you can only copy individual files.
