The importance of speech in the context of Buddhist ethics is obvious:
words can break or save lives, make enemies or friends, start war or create peace.

Buddha explained right speech as follows:

1. to abstain from false speech, especially not to tell deliberate lies
2. to abstain from slanderous speech and not to use words against others
3. to abstain from harsh words that offend or hurt others
4. to abstain from idle chatter that lacks purpose or depth.