In Snowflake, Streams are the objects that track Data Manipulation Language (DML) changes made to tables, such as inserts, updates, and deletes. Streams record these changes along with metadata about each change, enabling actions to be taken using the changed data. This process is known as change data capture (CDC)2.

To list all network policies available in an account, the correct command is SHOW NETWORK POLICIES.
Network policies in Snowflake are used to define and enforce rules for how users can connect to Snowflake, including IP whitelisting and other connection requirements. The SHOW NETWORK POLICIES command provides a list of all network policies defined within the account, along with their details.
The DESCRIBE SESSION POLICY and DESCRIBE NETWORK POLICY commands do not exist in Snowflake SQL syntax. The SHOW SESSION POLICIES command is also incorrect, as it does not pertain to the correct naming convention used by Snowflake for network policy management.
Using SHOW NETWORK POLICIES without any additional parameters will display all network policies in the account, which is useful for administrators to review and manage the security configurations pertaining to network access.
Reference: Snowflake Documentation on Network Policies
(https://docs.snowflake.com/en/sql-reference/sql/show-network-policies.html)