Computer Networking Pictures

Computer networking links together computers, information and resources through various hardware. Take a look at the history and types of computer networking and the components involved.

One of the first computer networking successes was in 1940, when George Stibitz used a teletype machine (seen above) to send data to a remote complex number calculator.

In the late 1950s, the military began using computer networks for a radar system called Semi-Automatic Ground Environment. Then, in 1960, two mainframe computers like the ones pictured above were connected to an online commercial airline reservation system.

Leonard Kleinrock, pictured here, was one of the first to develop network systems using data packets in the 1960s. His Host computer became the first node of the Internet in September 1969, establishing the network on the next page.

Wide Area Networks (WAN) were first developed in 1965. These telecommunication networks connect across cities, regions and countries. The Internet is the largest WAN, covering the globe. Learn how it formed next.

Before the Internet, there was the Defense Department's ARPANET, one of the most influential early computer networks (seen here in a 1969 drawing). The goal was to link different computers together, both to increase overall computer power and to decentralize information storage. Remote login, e-mail and file transfers became available for the first time.

The groundwork for the Internet became available with ARPANET, and in 1974, Vinton Cerf, seen here before a speech at Temple University in 2004, helped create Transmission Control Protocol/Internet Protocol, the language used to carry information over the Internet.

Just the year before, on May 22, 1973, the Ethernet was developed and set a standard for wired network connections. The original Ethernet sent communication over a single cable shared by all devices on the network, creating a local area network or LAN.

LAN networks can connect hundreds of computers, usually in close proximity to each other. Modern advancements have increased these distances considerably, allowing Ethernet networks to span tens of kilometers.

In a LAN, the cables connect to a device, such as a computer, and network switches, which connect different network segments and processes and route data.

For a LAN to connect to the Internet, an internet server is required. A server has a static IP address that does not change very often. The IP stands for Internet Protocol, which is the language that computers use to communicate over the Internet.

In home networks, the Internet server or service provider can be a modem, such as the broadband one pictured here. Modems came into existence in the 1960s as a way to allow terminals to connect to computers over phone lines.

Local area networks can also use power-line networking for a cable-free network. It uses the wiring already in your house to connect your computers.

Many businesses also have a virtual private network (VPN) that uses a public network (usually the Internet) to connect remote sites or users together. This allows the LAN network to expand.

A router links a private or business local area network to the Internet. Data traveling through the router, called packets, is then sent off to a destination via the best available route.

Routing all systems through IP means having just one network to maintain and upgrade.

A router can provide wireless and Ethernet connections, while also acting as a firewall. The firewall filters the data packets coming from the Internet connection before they enter your private network. Learn more about wireless networks on the next page.

Starting in the 1990s, wireless networks made it easy to connect to the Internet just about anywhere. A computer's wireless adapter (usually built-in) translates data into a radio signal and transmits it using an antenna. A wireless router receives the signal and decodes it. The router sends the information to the Internet using a physical, wired Ethernet connection.

There are several types of wireless networks, including wireless PAN, LAN and MAN networks. A PAN, or personal area network includes Bluetooth, a short-range wireless networking standard that you often see at work in wireless earpieces like this one.

A WLAN, or wireless local area network, uses radio signals to connect nearby devices, such as a computer to a wireless printer. This type of wireless network is based on 802.11 networking standards set by the IEEE, who sets standards for a range of technological protocols. There are variations within 802.11, depending on how strong the transmitter is, so an 802.11g router would provide a signal across a greater distance than 802.11b.

Wireless metropolitan networks (MAN) such as WiMAX provide high-speed Internet access at much greater distances than wireless LANs can. A MAN requires a transmitting tower and a receiver and is typically operated by a government entity.

Networks today are increasingly becoming more mobile, so you don't have to be at home or at work to get connected. For example, most mobile broadband services simply require the use of a card that allows users to access the Internet.

Mobile routers like this one also ensure that you're connected to the Internet wherever you roam.

Another emerging wireless technology is WiGig, which promises speeds up to 10 times faster than today's wireless LANs and is backward compatible with the IEEE 802.11 standard.

Cloud computing systems are also using computer networks in a new way. Local computers no longer have to do all the heavy lifting when it comes to running applications. The network of computers that make up the cloud handles them instead. To learn more about computer networking check out the Networking Channel and take our Home Networking Quiz.