Running ps in a jail will show the processes in the jail only.
Processes in the jail will only see network interfaces and other devices that have been explicitly exposed to the jail.
As others have said, it's like a vm with no virtualization overhead. You can set up jails with the entire Freebsd fs hierarchy so it runs like another host with its own users. Note that even the root user in a jail is not the same as the real root user. You can then use pkg to install packages within the jail too.
Processes in the jail will only see network interfaces and other devices that have been explicitly exposed to the jail.
As others have said, it's like a vm with no virtualization overhead. You can set up jails with the entire Freebsd fs hierarchy so it runs like another host with its own users. Note that even the root user in a jail is not the same as the real root user. You can then use pkg to install packages within the jail too.