Raw socket
Raw socket is a computer networking term used to describe a socket that allows access to packet headers on incoming and outgoing packets. Raw sockets are usually used at the transport or network layers.
Usually raw sockets always receive packets with the header included (as opposed to non-raw sockets, which strip the header and receive just the payload). Whether or not a header is automatically prepended to outgoing packets is usually a configurable socket option.
Due to the fact that raw sockets allow users to craft packet headers themselves, their power can be abused to perform feats such as denial-of-service attacks.
Raw sockets are not a programming language-level construct, they are part of the underlying operating system's networking API.
Resources
Net::RawIP; module for PERL applications. Created by Sergey Kolychev.