I have always laughed when I heard the phrase “smacked bottom” having friends that are from the UK apparently that is what they say instead of “spanking”. It honestly sounds more intelligent.
@SuziSatan02 For me,"smack" was just one or two smacks, by hand as you say. Spanking was longer and more formal, but still usually by hand. If an implement was used, then you were "caned" or "got the strap". At junior school we talked about getting "the whack". I'm sure there were many variants.