The world of computer terminology, and in particular network terminology, can be a bewildering place to the uninitiated.  With all the acronyms of computer terms and redefinitions of common terms, listening to two people talk about networking can sometimes be the equivalent of trying to follow a conversation in Vulcan.  This can be an especially frustrating predicament when you begin the search for a home or business networking solution.  

Although far from comprehensive, we've put together a list of some common networking terms and definitions.  After reading this you may not be able to wire your own office, but you'll at least understand enough to understand the network guys.  You'll be better prepared to ask the right questions and make the right decisions about your networking solutions.   

Networks 
According to LearnThat.com, "A network is a collection of terminals, computers, servers, and components which allows for the easy flow of data and use of resources between one another."  In other words, pretty much any time you hook up two or more computers you're creating a network.

There are dozens of types of networks.  The two you'll probably encounter the most will be LANs and WANs.

• LAN (Local Area Network).  A local area network, as the term suggests, networks a local area.  This local area can be as small as a home office or as large as an entire office building or university campus.   A LAN will allow shared access to such things as printers and fax machines and may allow computers to share files with each other.  If you've ever been in an office where you all used the same printer(s), you've probably used a LAN.

• WAN (Wide Area Network).  WANs span larger physical distances than LANs and are actually used to connect several LANs together.  The Internet itself is a WAN than connects countless home and office computers across the world.  WANs, however, do not have to be as large as the the whole Internet.  They may connect several office buildings across a city or computers from several government agencies.  Unlike LANs, WANs are typically organized and managed under some sort of collective ownership, and do not usually belong to just one person or office building.

Network Connections
There are several pieces of hardware and/or software responsible for connecting networks with themselves and with other networks.  Here are a few of the major ones.

• Router.  A router is a physical piece of equipment that joins two or more networks together.  You've probably seen a router although you may not realize it.  A DSL or cable modem (such as supplied by SBC or Roadrunner) are routers that connect your home LAN to the WAN of the Internet.  

• Hub.  The hub is the computer equivalent of a phone line splitter.  If you want to connect two phones to one phone line, you plug them into a splitter.  If you want to connect two (or more) computers to a network, you plug them into a hub.  Hubs are basically not-very-smart boxes.  That is, they do not read or alter the data going through them in any way.  They just move it on along to where it needs to go.  A common home connection is to run two or more computers through a hub which is then connected to a router that connects the home to the Internet.  

• Cables.  And of course you need the wires (or cables) that connect everything.  There are tons of different types of cables.  The cable choice depends on network protocols you are using, the speed you need, and the distance over which you need to send data.  

• Gateway.  A gateway is a very broad term that encompasses anything that joins two networks together.  Gateways do not have to be hardware (like a router), but can be software (like a firewall used for security).  Gateways are nodes that connect the Internet.  At a gateway the data you send or receive can be stopped, boosted, redirected or screened for safety.  The important thing to remember about gateways is that they don't refer to just one piece of equipment or software, but are a generic and very unspecific term used to indicate points or nodes in the Internet web where a data signal is directed or modified.  

• Firewall.   A firewall is a safety device to protect from hackers and other unauthorized access to your computer.  A firewall can be hardware (like a whole proxy server computer that sorts incoming data) or a software program on a personal or office computer.  

Network Models

Once a LAN or WAN has been build, the relationships between the computers in the network must be defined.  There are several different ways these relationships can be defined.  However, the Client-Server and Peer-to-Peer (P2P) models are the most common.

• Client-Server Model.  The client-server model is the most popular network model.  It is based on the idea that a client requests an information or service from a server who then returns the requested data.  When people speak of clients and servers on the Internet, you--the user at home or at an office--are usually the client.  When you type in an Internet address into your browser, it requests the web page information from the server that is hosting the website.  In a client-server model, computers may be built differently (i.e. with more memory, graphics capabilities, RAM, etc.) depending on whether or not they are intended to be clients or servers.    
• Peer to Peer.  According to Webopedia, a peer to peer Model is "a type of network in which each workstation has equivalent capabilities and responsibilities. This differs from client/server architectures, in which some computers are dedicated to serving the others."  Under such a system all computers can equally send or receive data, act as file servers or fax servers.  

Another term that is useful to know is intranet.  This is a generic term used to refer to a LAN usually developed by a company to improve communication between company employees.  It might supply for internal email, message boards, chat rooms, shared printers & faxes or a private website meant to provide company news and frequently accessed information.

Network Protocols
You can't just plug two computers together and assume they are going to know how to 'talk' to each other.  Network protocols define the rules of how data is packaged, organized and sent from one computer to another.  If you have one computer using one protocol and another using another, they won't be able to communicate.   Your entire network needs to be using one, agreed-upon protocol.

• Ethernet.  Ethernet is the most widely used protocol for LAN networking.  With Ethernet, each computer will check to see if another is transmitting before it begins to send data.  If two data streams accidentally collide, the computers will wait before they take turns sending their messages again.    

• Token Rings.  Token Rings are the second most widely-used network protocol for LANs after Ethernet.  In token rings, empty data packets are continuously circulating the network.  When a computer wants to send data, it inserts a 'token' data packet into an empty packet and sends it on.  Each computer in the network will examine the packet to see if it is the intended destination of the token.  When the correct computer is reached, it will send back the token to the original computer to let the computer know that the message has been received.   

• ATM (Switching Networks).  ATM (Asynchronous Transfer Mode) is usually used for WAN rather than LAN connectivity.  ATM uses switches (a sort of smart hub that can scan and direct packets) rather than the routers used in Ethernet and Token Rings.  These switches allow data to pass directly from the source to the end-receiver.  Also unlike the Ethernet and Token Rings, ATM protocol supports only fixed-sized data packets.  The absence of routers and the fixed-size of packets allows bandwidth to be more closely controlled with ATM networking.  

These are the three most common network protocols used at the most basic level of communication between computers in a LAN network.  There are many, many other types of protocols, both on this level and on higher levels of communication.  HTTP (the language that websites are written in) and FTP (a way to upload/download files and websites to and from servers) are also considered protocols.  There is one other very important protocol we should mention here.

• IP.  IP (Internet Protocol) is listed separately here from the above protocols because it resides on a different layer of communication.  That is, it rides 'on top of' the protocols above.  This protocol is the protocol that defines the addressing and data organization as opposed to the protocol for the sending of information controlled by the Ethernet, Token Rings and ATM protocols.  You may think of this protocol as defining how you need to write the address information on a letter as opposed to the above protocols which define the protocol needed to make sure that two mail trucks don't end up at your mail box at the same time.  
  
  You may have heard the term IP address.  This is short for "Internet Protocol Address" and refers to your computers physical address on the Internet.  This is the address for your computer in the same way that 100 Elm St, North Dakota may be the address for your home.  When data is sent from a computer to another computer it must have an originating IP address and a destination IP address.  This address information is contained within IP packets.  Each packet of data sent includes a header with source and destination IPs and the message itself. 

Cables

Different cables are appropriate for different network protocols, types, speeds and sizes. Below are a few of the most common cables you may hear mentioned. 

• Fiber Optic Cable.  In fiber optic cabling solutions, electrical signals are converted to optical signals and transmitted through an extremely thin glass fiber or cable.   Fiber optics are fast and maintain clear signals, but are more expensive than other wiring solutions.  Fiber optic cables are often networked through FDDI (Fiber Distributed Data Interface) which is a protocol based on two token rings.  FDDI-II can transmit voice as well as data signals.  Single-mode fibers are thinner, transmit farther and are more expensive than multi-mode fibers.  

• Twisted Pair & CAT5 Cables.  Twisted pair cables are exactly what they sound like--two pairs of wires twisted around one another.  Due to complicated rules of physics and electromagnetic signals, twisted wires help to reduce noise, or interference, on the lines.  CAT5 stands for Category 5 and is the fifth generation of twisted cabling.  It is currently the most popular form of twisted cabling for LAN networks.  UTP (Unshielded Twisted Pair Cabling) is a type of twisted cable where the inner wires have no shielding or casing but all four wires are enclosed in a common sheath.  

• Coaxial (thin) Cable.  Coaxial cable is an alternative to the CAT5 Twisted Pair and  Fiber Optic Cables. It is a copper cable surrounded by a layer of insulation which is surrounded by another copper channel and another layer of insulation.  Both channels run along the same axis (hence the name coaxial cable).  The outer channel serves as a ground.  

Two More Terms
Actually there are a billion more terms, but only two more we would like to make mention of here:

• Voice Networking Vs. Data Networking.  Because we are now often using the same lines for telephone and computers, the terms voice and data networking have evolved.  Voice networking is often just a fancy way of saying 'phone lines'.  Certain networks can support your phone lines (for voice) and your data lines (for computers) using the same wiring.  Other networks will have these two types of networks separated out.  Still other networks will allow for voice transfer as data using the same IP protocols used to transmit computer data. 

• ICS (Internet Connection Sharing).  ICS is a software program provided by Microsoft with Windows 98 and above.  ICS substitutes for a router and allows multiple computers in a home or office to be connected to one Internet connection.  It lacks some of the advantages of a hardware router but because it comes with Windows, ICS allows you to save on the cost of a router and is sometimes more convenient for beginning networkers.