I would say that they mean more or less the same thing but are used differently depending on the context or set expressions. Here are a few examples...Originally Posted by Оля
- c'est ma parole contre la tienne = it's my word against yours
- qui veut la parole ? = who wants to speak
- il va lui dire deux mots = he'll give him/her a piece of his mind
- il ne sait pas un mot de russe = he doesn't know a word of Russian
Of course these two terms also have a few meanings of their own.