Unsubscribed contacts are the ones who have opted out of your mailing list by their choice. By doing so, they specify that they no longer wish to receive any email communication from your end. 

A deactivated contact is created by a Freshsurvey user. This option comes in handy when some very sensitive accounts/ customers should not be disturbed or bothered by your surveys. Or when a contact has specified that they don’t want to be contacted.