Avatars:
Representation is how we get the stuff in our heads in some agreed format on some agreed media so other people can interpret what's in our heads but what's in our heads isn't the same as what we end up with as an illustration of the stuff that's in our heads. Then, the stuff we've made, in agreed format and using the agreed media is consumed, viewed, heard, felt, smelt, tasted, (Why not communicate with cooking, it appeals to me). Whatever, it is then compared with stuff that the receiver has already in their head and a suitable referant is guessed.
There are many and various kinds of representation deploying many different languages or forms. They can be expressive or they can be designed as impressive, abstract even expressively abstract.
One particular kind of representation are avatars. Avatars stand in place of that which can't actually be there.
Avatars were first used for Vishnu. The word has it's linguistic root in the Sanskrit word 'avatara' which means going down, which is derived from avatarati which combines, 'ava' which means 'down' and 'tarati' which means 'he passes over'.
It referred to Vishnu being manifested in human, superhuman, or animal form in the earthly realm. A representation of the deity.
Avatars are also used to represent some abstract concept that you can't take a picture of or draw such as an archetype.
Now since the first days of Macs and Windows operating systems the use of icons has been made use of to assist the command line challenged. Icons are little pictures that are linked from the GUI (Graphic Used Interface) to some command, file or executable. As desktop computing has developed and the internet grown in available bandwidth so have the sites dealing with such interesting activities as social networking thrived. These sites deal with the interactions between real people in a virtual environment. Real people manufacturing representations of meaning in sound text and images for other real people.
Now here is the point! People are far too big to squeeze down the wires so they came up with the ideas of using icons to represent those people. Now since people are usually though of as more important than anything else they get to use a special word to represent the little pictures that they use to represent themselves. So we choose pictures to represent ourselves and in true human form use the word originally built to represent a deity, which of course is 'avatar'.
Now this is where it gets really interesting. The selection of a picture is us saying stuff in a visual form about ourselves and was the subject of a really insightful blog by some cove here on Thought some time in the distant past.