SqlParameterCollection.Add with a size of -1

Question

What does it mean if you add a parameter to a query and set its size to -1?

Example:

sqlCommand.Parameters.Add("@data", SqlDbType.VarChar, -1).Value = jsonData;

Answer 1

This is the size you need to set for fields within a database that have a size of MAX IE. varchar(max) / nvarchar(max) etc