This Server Audit object will be responsible for collecting server and/or database-level actions and groups of actions that you want to monitor and is created at the instance level. This also means that if you have multiple instances running on a server, you would have to create Server Audit objects per instance.
Since both the server audit object and database audit specification are disabled by default after creation, we need to enable them. To verify their state, you can query the sys.server_file_audits and the sys.database_audit_specifications system objects. The is_state_enabled column would tell us of their state.