:-) is a popular emoticon that represents a smiley face. On some web interfaces, an actual illustration of a yellow smiley face appears when you type in these punctuation marks; on other interfaces, only the punctuation marks appear.
While most people consider communication with emoticons to be a relatively new phenomenon, according to Mashable, computer users have been using them for close to 30 years. In fact, emoticons go back even further to the days of letterpress and movable type. One of the first instances of the use of emoticons is a New York Times transcript of a 1962 speech by Abraham Lincoln.