Difference Between Char and Varchar in SQL Server

Below list is major difference between Char[n] and varchar[n] Datatype in Sql Server;

Type	char[n]	Varchar[n]
Storage Type	Char is fixed length of datatype. If you declare variable with 20 character length. Like Char(20), it takes 20 bytes regardless storing 1 or 20 character.	varchar is fixed length of datatype. If you declare variable with 20 character length. Like varchhar(20), it takes number of bytes as defined.
Storage Example	DECLARE @Name Char(20) = 'Bob'  SELECT DATALENGTH(@Name) as Result Result ----------- 20	DECLARE @Name VarChar(20) = 'Bob'  SELECT DATALENGTH(@Name) as Result Result ----------- 3
Performance	If your content is fixed size than Char datatype has good to use.	It is performing better than char if variable datatype.
Which should Use	Data can have Unicode characters.	Data doesn’t have any Unicode characters.