When creating or updating a SSH user you will be required to choose one or more containers or volumes that you wish to grant the user access to. This allows you to easily use the same SSH user across multiple containers or volumes without having to create multiple users.
Users that are created as part of the container creation process will automatically have access to the new container being created.
It is important to note that assigning multiple containers to a user will affect the number of commands that are available to the user.
For more information on this, please see our article on SSH User Privileges.