A round, yellow, smiling face. A popular icon of the sixties.

or

A smiley face is used to express one's joyful emotions on the emotionless medium we know as the Internet. You normally tilt your head to the left to see these critters. Here are some examples:

:), =), :], =], 8), 8] are your basic smilies.
;), =>, :> is used when you've made a flirtatious or sarcastic remark.
>:) is a mischievous grin.
(: is a left-handed smiley. (Tilt head to the right).
:D is a big-toothed grin or laughter.
:O is also laughter.
B) is a sun-glassed smiley.

Please note that variants use a -, o, or something else between the : (eyes) and ) (mouth) to make a cute little nose. Happy smiling.