What's the difference between unsubscribe, optout?

[mcarson]

We having been using CiviMail 'live' for quite some time now and have just started using CiviEvent. We are very impressed with the results, however we are anxious that our unsubscribe/opt-out messages are not understood by the recipients of our mailings.

Am I correct in stating:
"To unsubscribe from further event invitations, you can reply with this link: {action.unsubscribeUrl}"
"To opt-out from ALL bulk mailings, you can reply with this link: {action.optOutUrl}"

It works well when one of our contacts decides to opt-out with their record changed for "User Opt-Out", but for unsubscribes it can be confusing...

To clarify:
Any one contact in our system can be a member of one or more mailing groups. If a mailing recipient unsubscribes using the link from a particular mailing when more than one group is used, from what group is the contact removed from? A random group or all of them.

[Donald Lobo]

we remove them from ALL the mailing groups that they've been subscribed to that were sent this mailing

lobo