Wikipedia Definition
Wikipedia defined AA as "...a graphic design technique that uses computers for presentation and consists of pictures pieced together from the 95 printable (from a total of 128) characters defined by the ASCII Standard from 1963 and ASCII compliant character sets with proprietary extended characters (beyond the 128 characters of standard 7-bit ASCII). The term is also loosely used to refer to text based visual art in general. ASCII art can be created with any text editor, and is often used with free-form languages. Most examples of ASCII art require a fixed-width font (non-proportional fonts, as on a traditional typewriter) such as Courier for presentation."
It is never actually known when ASCII Art was originated, but the oldest example of an ASCII art are creations by computer-art pioneer Kenneth Knowlton from around 1966, who was working for Bell Labs at the time.
Variations
AA Characters
AA Characters are text generated characters that are known, and generally well received by the Japanese, and also popular in the largest bulletin board system, 2ch - a lot of ASCII arts are created by the denizens of 2ch and has since spread wide across many anime blogs and even chatrooms.
Tags that are tagged "AA" are illustrations that are highly related to these creations, such as Monā.
General
Monā (or Mona)
Giko
Morarā
Shii
1-san
Eight Headed Monā
Nidā
Gyasha
Pororo
Urara
Tsuu
Noo
Jisakujien
Morara
Onigiri
Deii
Dokuo
Utsudashinou
Takaragiko
Youkan Man
Yaruo
Yaranaio
Oden Man
Aramaki Skullchef
Kumaa
Shoboon
Minna~
Shimamura-kun
Naitou Horizon
Joruju Nagaoka
Dateikuuru
Boom-kun
Caesar Nishiwaki
Analog Bear
Sasuga Brothers
コテキャラ
AAs that are created and enhanced by AA creators at Mona board.
March Hare
Excellency
Ragi
Shii
Similar Tags：コテハン こてきゃら創作
AA Series
This is mainly for AA based stories created by the 2ch denizens
世界制服をたくらむモララー
山奥のしぃ先生
Shii's Atelier
Video Rack
The Flaming Fallen Angel
AA Memes
AA based meme that are made famous by 2ch due to them spreading wide across the boards, and eventually, outside 2ch and sometimes even the world.
Note: These translations are not final, tags can be subjected to change at any time.
Don't Look Here (こっちみんな)
Heaven Situation (ヘブン状態)
マジックテープ
Yada Yada (ヤダヤダ)
＼(^o^)／
Tanyao (タンヤオ)
I'll Make Fried Rice (チャーハン作るよ!)
Why Has it Turned This Way (どうしてこうなった)
どうしてこんなになるまで放っておいたんだ
I Refuse (お断りします)
BRB Going to Konbini (ちょっとコンビニ行ってくる)
Such Reckless… (無茶しやがって…)
Let's Take it Easy (ゆっくりしていってね)
エビフライぶつけんぞ
Discussing (審議中)
お前それサバンナでも同じこと言えんの?
Trace AA
Existing images(Illustrations, pictures, etc) or screenshots that are traced and converted as an AA
