There are at least three different kinds of feedback that may be appropriate in a given situation:
APPRECIATION is expression of gratitude or approval of another’s effort. It is an expression of emotion, designed to meet an emotional need.
ADVICE (or COACHING) consists of suggestions about particular behavior that should be repeated or changed. It focuses on the performance, rather than judging the person.
EVALUATION is ranking the subject’s performance in relation to that of others or against an explicit or implicit set of standards.
The habit you want to develop is to know your purposes when you offer feedback, and to make your comments in a form appropriate to accomplishing that purpose.
Source: How to Provide Great Feedback When You’re Not In Charge