In today's society, more people and businesses rely on computers and networks to store vital information and technology.
Networking is the process of moving information via computers rather than via any other medium, such as paper media or mere human communication. In addition to sharing information via networks, computers can share hardware, e.g., laser printers, and software in the networking process. This can save businesses and individuals large sums of money.
The computers or devices on a network are often referred to as "nodes."
To visualize a network, the easiest image is that of two computers hooked together by a cable, transmitting information between the two machines.
There are actually a variety of kinds of networks, e.g., local area networks (LANs) and wide area networks (WANs).
LAN is a relatively localized network:
LAN is a high-speed data network that covers a relatively small geographic area. It typically connects workstations, personal computers, printers, servers, and other devices. LANs offer computer users many advantages, including shared access to devices and applications, file exchange between connected users, and communication between users via electronic mail and other applications."
By contrast, a wide area network is a less centralized network, allowing computers that are located in remote locations to be connected. In essence, a WAN is:
group of devices located remotely and connected via some electronic means, i.e. telephone system, satellite link, etc. What this really means is a large group of computers linked together via hardware and software in an unlimited area. This network may be across town, between cities or between continents. Generally, the network has one or more LANs containing servers for file and print applications, printers for document output and a number of workstations for the end users. All of these resources are normally physically connected locally via some form of cable (i.e. coaxial, twisted pair, etc.) to a hub and/or router which is then connected to a telephone system, satellite link or other form of electronic transmission."
II. Home Networks, Intranets, and the Internet
Three different kinds of networks -- the home network, intranets, and the Internet -- will now be discussed. The home network is the simplest of the networks to be discussed, and the Internet connects the widest range of people. The corporate "intranet" is built on the same technology as the Internet. However, an intranet is designed to be utilized for a company's internal purposes.
A. Home Networks home network essentially allows individuals to link together all of the computers in their home. A home network can allow a family to save money on multiple peripherals such as printers and fax machines and allow the family to access all of the computers and software stored within the computers linked in the household.
In addition, "one of the most compelling reasons to set up a home network is that everyone can be on the Internet at the same time."
More than half of the homes in the United States have a computer, and a significant number of those have more than one computer in the household. (International Data Corp.) Therefore, home networking is becoming increasingly common and beneficial in the United States.
However, as is the case with larger networks, there are security risks associated with home networks, especially with "always on" broadband Internet services such as DSL and cable modems. Common forms of security attacks include email spoofing, Trojan horses, and email born viruses.
Therefore, home users must weigh the benefits and risks of setting up a home networking system. Relatively simply ways of protecting the security of a network include building a firewall to protect internal computers and servers, using virus protection software, making routine backups of crucial data, and turning off the network when it is not being used.
By far, however, the largest and most global network is the Internet. Most people do not think of the Internet as a network, but it is the most wide-reaching and revolutionary type of network that exists today.
The Internet is built using underlying network protocols called Transmission Control Protocol (TCP) and Internet Protocol (IP).
TCP and IP were designed by the United States Department of Defense to connect a multitude of different networks.
Today, these are the network protocols used worldwide to connect people via the Internet:
The TCP/IP protocol suite has become the de facto standard for computer communications in today's networked world.
The protocols can be run on multiple hardware platforms across the globe.
For computers to network via the Internet, they must each have a unique "address" and be on an "IP" network.
IP "handles the transmission of data from an originating computer to the computer specified by the IP address. It does so by breaking up large, unwieldy chunks of data into easily manageable IP packets that it can deliver across the network."
An IP address locates the computer and the computer's network adapter. Moreover:
a]n IP address can be private, for use on a LAN, or public, for use on the Internet or other WAN. IP addresses can be determined statically (assigned to a computer by a system administrator) or dynamically (assigned by another device on the network on demand). IP addresses consist of four bytes (32 bits). Each byte of an IP address is known as an octet. Octets can take any value between 0 and 255, but various rules exist for ensuring IP addresses are valid."
Most of us are familiar with IP addresses that look something like www.domainname.com, butthese IP addresses correspond to numerical counterparts - such as 126.96.36.199 -- which are not used for marketing purposes because they are difficult to remember.
IP addresses are basically the online equivalent of offline mailing addresses.
In terms of impact, the Internet is the most significant of all types of networks because of its global reach. Anyone, anywhere on the globe can connect to anyone located anywhere else on the globe so long as both people have access to a computer that is Internet enabled.
Many corporations have a need for their employees and/or clients to communicate privately via the Internet. In the past, to set up such a proprietary communication network, they would have to set up an extremely expensive, tailor-made database system that would generally not be accessible to external clients unless they were provided with software to access the database. Today, however, corporations can simply build a corporate intranet.
An intranet is a private, secure space on the Web where all members of [a] group can communicate with each other, share information, and collaborate on projects."
An intranet is basically just a private web site for a company's intended users, such as employees, vendors, independent contractors, consultants, and clients. Only those to whom the company grants access (through a password) may enter the intranet through any computer that is Internet-capable.
Again, network security is an issue with intranets, but it is even more an issue with intranets because outsiders are being granted access to a company's internal data. Therefore, it is advisable that company's build separate pages for internal use, i.e., for employees, and for external use, e.g., for suppliers and clients.
Computer Networking." ComputerNetworking.com. July 4, 2002. http://compnetworking.about.com/library/glossary/bldef-ipaddress.htm.
CERT Coordination Center, "Home Network Security." Cert.org. July 4, 2002 http://www.cert.org/tech_tips/home_networks.html#III-A.
Gilbert, H., "Introduction to TCP/IP," Yale.edu. February 6, 1995. Yale University. July 6, 2002 http://www.yale.edu/pclt/COMM/TCPIP.HTM.
IBM Redbook Abstract, "TCP/IP Tutorial and Technical Overview." IBM.com. July 5, 2002. IBM, Inc. http://publib-b.boulder.ibm.com/Redbooks.nsf/RedbookAbstracts/gg243376.html?Open.
Intranets.com, "What is an Intranet?" July 4, 2002. http://www.intranets.com/ProductInfo/Intranet.asp.
Ivens, Kathy, Home Networking for Dummies, (John Wiley & Sons, 2002) p.20.
Sol, Selena. "Internet Protocol." August 16, 2000. WDVL.com. July 5, 2002 http://www.wdvl.com/Authoring/Tools/Tutorial/IP.html.
Tyson, Jeff. "How Home Networking Works." HowStuffWorks.com.
Marshall Brain's How Stuff Works. http://www.howstuffworks.com/home-network.htm/printable.
What is a LAN?." Cisco.com.
July 4, 2002. Cisco, Inc. http://www.cisco.com/univercd/cc/td/doc/cisintwk/ito_doc/introlan.htm#xtocid2.