Regular character types versus Unicode types

Whenever you setup a table in a Microsoft SQL database you have to choose between using regular character (CHAR, VARCHAR) or Unicode (NCHAR, NVARCHAR) data types for storing string values in a column. Regular character types only support one language besides English and uses 1 byte of storage per character. Unicode data types supports multiple languages and uses 2 bytes of storage per character unless compressed. If a surrogate pair is need then that character will use 4 bytes of storage.

So for if your data is in multiple languages you should should use a Unicode data type but if you only need to represent just English or English plus only one other language you should use the regular character types which have lower storage which will result in better performance.