inetd It’s daemon listens on specific ports such as (telnet 23, ftp 21), when it receive a packet, it’s lunches the appropriate program to handle the connection.
Xinetd It does the same work as inetd, but with more security such as (TCP Wrapper).
TCP Wrapper It supports TCP/IP security by using (Access Control List), it works with Xinetd to support security for some services such as telnet or ftp even SSH.
