What is the difference between CHAR and VARCHAR datatypes in SQL Server?

CHAR and VARCHAR are both data types used in SQL Server to store character data, but they have key differences.

CHAR Datatype:

• CHAR is a fixed-length data type, meaning it requires a predetermined amount of storage space regardless of the actual data length.
• CHAR values are padded with spaces at the end to fill up the defined length.
• CHAR is suitable for storing data where the length is consistent and known in advance.

VARCHAR Datatype:

• VARCHAR is a variable-length data type, meaning it only uses storage space equal to the actual data length, plus 2 bytes to store the length information.
• VARCHAR does not pad the stored values with spaces, making it more storage-efficient for variable-length data.
• VARCHAR is suitable for storing data where the length varies and is not known in advance.

When choosing between CHAR and VARCHAR, consider the expected data length and storage efficiency requirements of your database.