Subjective feelings: there is a conscious awareness of change in core affect.
Example: when irritated by package difficult to open, we also feel irritated
Physiological reactions: changes in autonomic nervous system accompany affective experiences.
Example: dilated pupils, produce sweat when excited
Expressive reactions: facial, vocal , postural expressions accompany affective experiences
Example: we smile, frown, express body language when we are happy or unhappy about experiencing a new product
Behavioural reactions: actions one engages in when experiencing a change in core affect.
Example: we approach a product we find attractive or intriguing, we avoid those we find irrelevant to us, we attack those which offend or annoy us, we take good care of products which are memorable or irreplaceable to us.
More on this topic in this article:
Pieter Desmet & Paul Hekkert. 2007. Framework of Product Experience. International Journal of Design. Vol 1 No 1.