The `ALTER COLUMN` statement is a fundamental part of database management. It allows you to change the characteristics of a column without having to drop and recreate the entire table. This is often necessary when you realize that a column's current definition doesn't meet your requirements. For instance, you might need to change a column's data type, add a constraint, or modify its length. This flexibility is essential for maintaining a database that accurately reflects your application's data. Using `ALTER COLUMN` is generally preferred over dropping and recreating a table, especially in production environments, as it minimizes downtime and data loss. It's important to understand the implications of each modification before executing the statement, as it directly affects the data stored in the column.