What is the method for deleting a directory in Ubuntu?

In Ubuntu, you can use the following command to delete a directory:

1. Delete an empty directory using the rmdir command.
2. Remove directory at [path]
3. Remove a non-empty directory and its contents using the rm command.
4. Remove the directory at the specified path.

Please make sure to backup important files or directories before executing the delete operation, as it is irreversible.