By Vincenzo Mendillo
TCP/IP is a set of protocols that allow cooperating computers to share resources across a network. It was developed by a community of researchers centered around the ARPAnet. Certainly the ARPAnet was the best known TCP/IP network, but now has been replaced by the Internet. The most accurate name for the set of protocols we will describing is the "Internet protocol suite" or "Internet protocol stack". TCP and IP are two of the protocols in this suite and because they are the best known of the protocols, it has become common to use the term TCP/IP to refer to the whole family. So the generic term TCP/IP usually means anything and everything related to the specific protocols of TCP and IP. It can include other protocols, applications, and even the network medium. A sample of these protocols are: UDP, ARP, and ICMP. A sample of these applications are TELNET, FTP, TFTP, SMTP and SNMP. The Internet is a collection of international and national networks, regional networks, local networks at a number of universities and research institutions, and also a number of military networks. The term "Internet" applies to this entire set of networks. All of these networks are connected to each other. Users can send messages from any of them to any other, except where there are security or other policy restrictions on access.
Officially speaking, the Internet protocol documents are simply standards adopted by the Internet community for its own use. Internet standards are called RFC. RFC stands for Request for Comment. A proposed standard is initially issued as a proposal, and given an RFC number. When it is finally accepted, it is added to Official Internet Protocols, but it is still referred to by the RFC number. Whenever an RFC is revised, the revised version gets a new number. These documents are being revised all the time, so the RFC number keeps changing.