I have read an great technical article by Joel Spolsky. Actually it was written on year 2003 [October 08, 2003]. But read today.
ok, coming to point. That article is about basis of “Unicode Char sets”
title and URL,
The Absolute Minimum Every Software Developer Absolutely, Positively Must Know About Unicode and Character Sets (No Excuses!)
just tiny bit from that article,
Some people are under the misconception that Unicode is simply a 16-bit code where each character takes 16 bits and therefore there are 65,536 possible characters. This is not, actually, correct.
Lengthy article but worth reading. Make you free to read this.