As given by MySQL documentation (http://dev.mysql.com/doc/refman/4.1/en/charset-general.html): A character set is a set of symbols and encodings. A collation is a set of rules for comparing characters in a character set.
Why is MySQL Collation an important consideration?
Collation determines the rules in comparing characters including the case sensitiveness, accent sensitiveness, trailing space sensitiveness of the character set.
To know the available character sets in Mysql, type
mysql> show character set
Under the column listing “Default collation”, there will be a listing of collation identifying some character sets as “_ci” – case-insensitive and some as “_CS” – case sensitive character sets.
The order in which you expect the sorting of the resultset will be KEY factor in determing which COLLATION you would want to choose for your application.
If you were developing an application specific to a region catering your site needs to a specific language then it is important that you consider the correct character set which helps to determine, how the characters get displayed in the browser.