In SQL, VARCHAR is a data type used to store character strings of variable length, while CHAR is used to store character strings of fixed length. Here are some key differences between the two:

• Length: In CHAR, the length of the string is fixed and specified when the column is created, while in VARCHAR, the length of the string can vary up to a maximum length specified when the column is created.

• Storage: CHAR always uses the same amount of storage space per entry, while VARCHAR only uses the amount necessary to store the actual text.

• Padding: In CHAR, if the length of the string is less than the fixed length, it is padded with extra memory space, while in VARCHAR, if the length of the string is less than the maximum length, it will store as it is without padded with extra memory spaces.

• Usage: CHAR is used when the data values in a column are of the same length, while VARCHAR is used when the data values in a column are of variable length.

It is important to note that VARCHAR can hold numbers, letters, and special characters, and can store up to 8000 characters as the maximum length of the string using VARCHAR data type in Microsoft SQL Server 2008 (and above) .