Difference between Unicode and non-Unicode datatype ?

Unicode datatypes are nchar, nvarchar, and ntext .
Non-Unicode datatypes are char, varchar, and text .


Difference between Unicode and non-Unicode datatype are :

1. Unicode supports a wider range of characters.
2. More space is needed to store Unicode characters.
3. The maximum size of nchar and nvarchar columns is 4,000 characters, not 8,000 characters like char and varchar.
4. Unicode constants are specified with a leading N: N'A Unicode string'.
5. All Unicode data uses the same Unicode code page. Collations do not control the code page used for Unicode columns, only attributes such as comparison rules and case sensitivity.