Which file contains a set of services and hosts that will be allowed to connect to the server by going through a TCP Wrapper program such as tcpd?

Which file contains a set of services and hosts that will be allowed to connect to the server by going through a TCP
Wrapper program such as tcpd? (Specify the full name of the file, including
path.)https://lh3.googleusercontent.com/-5cd-clmKnbk/AAAAAAAAAAI/AAAAAAAAADM/-SXesH19Ido/s46-c-k-no/photo.jpg

A.
/etc/hosts.allow