Snowflake's secure data sharing feature allows the sharing of several database objects, including external tables and Secure User-Defined Functions (UDFs). These objects are specifically designed to maintain security and integrity while being shared across different Snowflake accounts. External tables allow data stored outside of Snowflake to be queried as if it were located within Snowflake, making them shareable. Secure UDFs allow users to define their own functions securely, maintaining the integrity and security of the shared function.