Concatenating strings is an essential operation when working with data in Snowflake, where it's useful for data normalization, transformation, and query optimization. The `||` operator and the `CONCAT` function are two methods to concatenate strings in Snowflake, both achieving the same result but differing in coding style preference. By using either method, developers can efficiently combine values from multiple columns into a single column, creating composite keys or optimizing queries for better performance and readability.