When you write ping example.com, the kernel cannot work with names; it
needs an IP address. The name has to be resolved, which is
dns-resolution. That work is handled by a combination of
/etc/hosts (a static local file), /etc/resolv.conf (the address of
the DNS server for everything that is not in hosts), and the NSS library
(it decides in what order to query them).
This sandbox has no internet, so real DNS queries going out will not go
through, but you can bring up local names through /etc/hosts and try
the getent, dig, and host tools.