An emoticon (/ɨˈmoʊtɨkɒn/) is a pictorial representation of a facial expression using punctuation marks and letters, usually written to express a person's mood. Emoticons are often used to alert a responder to the tenor or temper of a statement, and can change and improve interpretation of plain text.
(Wikipedia)
Tutorial:
How to Add Kolobok Emoticons in Blogger Comments