Unix Sockets : AF_LOCAL vs AF_INET

Question

I\'m just starting with socket programming in UNIX and I was reading the man pages for the socket system call. I\'m a bit confused about the AF_LOCAL argument and when it is use

Answer 1

AF_LOCAL uses UNIX domain sockets which are local to the filesystem and can be used for internal communications. AF_INET is an IP socket. AF_LOCAL will not incur some performance penalties related to sending data over IP. See this old but very nice discussion of the topic.