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
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.
Before the Internet, there was the Defence 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
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
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
Routing all systems through IP means having just one network to maintain and
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
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
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