Expanded std::net module docs

Part of rust-lang#29363

Author: chordowl

src/libstd/net/mod.rs

@@ -9,6 +9,32 @@
 // except according to those terms.
 
 //! Networking primitives for TCP/UDP communication.
+//!
+//! This module provides networking functionality for the Transmission Control and User
+//! Datagram Protocols, as well as types for IP and socket addresses.
+//!
+//! # Organization
+//!
+//! * [`TcpListener`] and [`TcpStream`] provide functionality for communication over TCP
+//! * [`UdpSocket`] provides functionality for communication over UDP
+//! * [`IpAddr`] represents IP addresses of either IPv4 or IPv6; [`Ipv4Addr`] and
+//!   [`Ipv6Addr`] are respectively IPv4 and IPv6 addresses
+//! * [`SocketAddr`] represents socket addresses of either IPv4 or IPv6; [`SocketAddrV4`]
+//!   and [`SocketAddrV6`] are respectively IPv4 and IPv6 socket addresses
+//! * [`ToSocketAddr`] is a trait that used for generic address resolution interacting
+//!   with networking objects like [`TcpListener`], [`TcpStream`] or [`UdpSocket`]
+//! * Other types are return or parameter types for various methods in this module
+//!
+//! [`IpAddr`]: ../../std/net/enum.IpAddr.html
+//! [`Ipv4Addr`]: ../../std/net/struct.Ipv4Addr.html
+//! [`Ipv6Addr`]: ../../std/net/struct.Ipv6Addr.html
+//! [`SocketAddr`]: ../../std/net/enum.SocketAddr.html
+//! [`SocketAddrV4`]: ../../std/net/struct.SocketAddrV4.html
+//! [`SocketAddrV6`]: ../../std/net/struct.SocketAddrV6.html
+//! [`TcpListener`]: ../../std/net/struct.TcpListener.html
+//! [`TcpStream`]: ../../std/net/struct.TcpStream.html
+//! [`ToSocketAddr`]: ../../std/net/trait.ToSocketAddr.html
+//! [`UdpSocket`]: ../../std/net/struct.UdpSocket.html
 
 #![stable(feature = "rust1", since = "1.0.0")]