Updated: 05/21/2018 by Computer Hope

Short for Transmission Control Protocol/Internet Protocol, TCP/IP is a set of rules (protocols) governing communications among all computers on the Internet. More specifically, TCP/IP dictates how information should be packaged (turned into bundles of information called packets), sent, and received, as well as how to get to its destination. TCP/IP was developed in 1978 and driven by Bob Kahn and Vint Cerf.

Network TCP and IP packet

How does TCP/IP work?

As the name implies, TCP/IP is a combination of two separate protocols: Transmission Control Protocol (TCP) and Internet Protocol (IP). The Internet Protocol standard dictates the logistics of packets sent out over networks; it tells packets where to go and how to get there. IP has a method that lets any computer on the Internet forward a packet to another computer that is one or more intervals closer to the packet's recipient. You can think of it like workers in a line passing boulders from a quarry to a mining cart.

The Transmission Control Protocol is responsible for ensuring the reliable transmission of data across Internet-connected networks. TCP checks packets for errors and submits requests for re-transmissions if any are found.

Three of the most common TCP/IP protocols

  • HTTP - Used between a web client and a web server, for non-secure data transmissions. A web client (i.e., Internet browser on a computer) sends a request to a web server to view a web page. The web server receives that request and sends the web page information back to the web client.
  • HTTPS - Used between a web client and a web server, for secure data transmissions. Often used for sending credit card transaction data or other private data from a web client (i.e., Internet browser on a computer) to a web server.
  • FTP - Used between two or more computers. One computer sends data to or receives data from another computer directly.

Domain names and TCP/IP addresses

The TCP/IP address for a website or web server is typically not easy to remember. To remedy this issue, a domain name is used instead. For example, is one of the IP address for Google and is the domain name. Using this method, instead of a set of numbers, makes it much easier for users to remember Computer Hope's web address.

What are the different layers of TCP/IP?

There are four total layers of TCP/IP protocol, each of which is listed below with a brief description.

  • Network Access Layer - This layer is concerned with building packets.
  • Internet Layer - This layer uses Internet Protocol (IP) to describe how packets are to be delivered.
  • Transport Layer - This layer utilizes User Datagram Protocol (UDP) and Transmission Control Protocol (TCP) to ensure the proper transmission of data.
  • Application Layer - This layer deals with application network processes. These processes include File Transfer Protocol (FTP), HyperText Transfer Protocol (HTTP), and Simple Mail Transfer Protocol (SMTP).

Related pages

FTP, IPX/SPX, NetBEUI, Network terms, Port, UDP