The other day I got to wondering about emoticons and emoji, and how they are the same or different. An emotion ("emotion icon") is of course the ASCII "smiley-face" that we've used for years in emails, online forums, text messages, and instant messages of all kinds to express emotions.  You know what I'm talking about -- these guys:
:-)  :-D  :P  :-(   8-)     

And so on.  Over the years users got cleverer and cleverer at creating emotions to express feelings without words.  For example @--\-- is a rose.  On its side.  Kind of.  

Wikipedia's entry on emoticons reveals a much more interesting history than I expected (check it out at http://en.wikipedia.org/wiki/Emoticon), but the invention of the "smiley face" emoticons is pegged at 1982.  About 10 years later, as Japan was developing mobile platforms and tools, standard pictographs known as emoji [the word emoji literally means "picture" (e) + "character" (moji)] were standardized and hard-coded into the character sets like fonts.  These proved VERY popular among the Japanese culturally, and as mobile technology became entrenched and spread through Asia and western Europe, the demand for emoji on the various platforms like Apple iOS spread as well.  It's only fairly recently since North America has taken to emoji.  Apple first introduced emoji to their desktop operating system with the release of Mac OS X 10.7 Lion in 2011.  (With the introduction of Mac OS X 10.9 Mavericks, users can now access a dedicated emoji input palette in most text input boxes by using the key combination.COMMAND+CONTROL+SPACE.)

Emoji include smiley-faces but also other pictures such as hands applauding, animals, national flags, flowers, and a lot of other things.  As such, they can be used to express far more complex information than the simple emoticons, which are largely limited to representations of facial expressions.  Emoji are static (they don't move) and brightly colored.  They are not fonts in and of themselves, but emoji come in character sets like fonts do.  Wikipedia's entry on emoji was interesting although emoji history is not as impressive as emoticon history (http://en.wikipedia.org/wiki/Emoji).

To make my emails and texts more interesting I use both emoticons and emoji.  I don't put a ton of thought into choosing one or the other; usually it depends on the message I'm writing and how fast I'm typing.  But now I feel a lot more informed about these non-text components of my messages!