SQL: Data type for image

Reference: 1, 2

The ntext, text, and image data types will be removed in a future version of SQL Server. Avoid using these data types in new development work, and plan to modify applications that currently use them. Use nvarchar(max), varchar(max), and varbinary(max) instead.

SQL: VARCHAR vs NVARCHAR

Reference 1

Reference 2

varchar is used for non-Unicode characters only on the other hand nvarchar is used for both unicode and non-unicode characters. Some other difference between them is given below.

SQL: VARCHAR(N) vs VARCHAR(MAX)

Reference

When choosing data type, we should consider the database design, performance, compression, and indexes in mind.

We can define a specific range for the varchar (n) data type, and it is the recommended way to do so.

Varchar (n) can store up to 8000 bytes of data using varchar (8000) data type.

Varchar (max) can store data up to 2 GB.

SQL: CHAR vs VARCHAR

Installing MS SQL Server 2019 Database and Integration Service