Is there a difference between Excommunication & Refusal of Holy Communion?

Are Those Calling for Excommunication and those calling for Refusal of Holy Communion after the same results?

Obviously there is a difference between Excommunication and Refusal of Holy Communion, but both factions are trying to control their political enemies (or so it seems) by using these means.

And both would argue that the individuals are ex-communing themselves by their behavior or publicly-held beliefs that are contrary to the traditional teachings of the Church and/or Sacred Scripture.

The word Commun is in both the word Excommunication and the phrase Refusal of Communion. And both are meant to bring someone back into full communion with the flock and not meant to be used as tools of division, though it often appears to be used as punishment for those who oppose the other’s vision.

Thoughts?