What is the difference between prophesying and preaching?

My understanding is that prophecy is not identical to preaching, but involves both forthtelling and foretelling. The reason women may prophesy but not teach or preach to men is that the message that the prophet gets from God is not filtered through the interpretive process—that is, it is directly mediated by the Spirit. Hence, in effect, prophecies are ‘tamper-proof,’ whereas teaching is not (cf. 1 Tim 2:12-14).