As introduced in Subsection 5.4.1, when you intend to open a socket for a connection between processes or hosts, you need to assign the domain argument as AF_UNIX and AF_INET, respectively. Below the...

As introduced in Subsection 5.4.1, when you intend to open a socket for a connection between processes or hosts, you need to assign the domain argument as AF_UNIX and AF_INET, respectively. Below the socket layer, how are different data flows and function calls implemented for sockets with different domain arguments? Are there other widely used options for the domain argument? In what kind of condition will you need to add a new option to the argument?