ASCII code
7or 8bits
2^7=128
2^8=256(128 extra)


pros
internationally recognized
little storage space required
data can transfer across devices and is recognizable
cons   
limited number of characters( not many bits to use)
not compatible with other languages
would need to software for separate languages

ASCII represents characters by assigning each character with a unique binary code of 7 bits
for example "Shaun Tocher" is repersented in ascii (binary) as the following;

0100100 1101000 1100001 1110101 1101110 1010100 1101111 1100011 1101000 1100101 1110010

but not all languages can fit within this system
Egyptian hieroglyphics has 700-800 characters 


English           Chinese             uni                                                  Binary 
Bannana        香蕉             香蕉of(香蕉 )      1001100110011001 1000010101001001



http://wiki.answers.com/Q/How_many_hieroglyphic_characters_are_there  
http://translate.google.com/#auto|zh-TW|Banana
http://software.ellerton.net/txt2bin/
http://www.chinese-tools.com/tools/converter-unicode.html