Whether you are a business manager learning the language of technology to better communicate with IT staff, or just beginning your IT career, don't overlook a basic understanding of computer networking.
What is computer networking?
The simplest definition of a computer network is a group of computers that are able to communicate with one another and share a resource. A computer network is a collection of hardware and software that enables a group of devices to communicate and provides users with access to shared resources such as data, files, programs, and operations.
Common networking terms
Each device on a network, is called a node. In order for communications to take place, you need the software, the network operating system (NOS) and the means of communication between network computers known as the media.
In computer networking the term media refers to the actual path over which an electrical signal travels as it moves from one component to another. The media can be physical such as a specialized cable or various forms of wireless media such as infrared transmission or radio signals. A network interface card (NIC) enables two computers to send and receive data over the network media.
What is a protocol?
A Network protocol is a agreed upon set of rules that define how network computers communicate . Different types of computers, using different operating systems, can communicate with each other, and share information as long as they follow the network protocols.
The Internet protocol suite commonly known as TCP/IP is a set of communications protocols used for the Internet and similar networks. You will often see the terms protocol suite or protocol stack used interchangeably. The protocol stack is an implementation of a computer networking protocol suite.
What is a LAN (Local Area Network) versus a WAN (Wide Area Network)?
In a typical LAN (Local Area Network) a group of computers and devices are connected together by a switch, or stack of switches, using a private addressing scheme as defined by the TCP/IP protocol. You may not be familiar with the specific function of a network switch or the definitions of private addressing scheme, they are more advanced topics of computer networking.
Private addresses are unique in relation to other computers on the local network. Routers are found at the boundary of a LAN, connecting them to the larger WAN.
In a WAN (Wide Area Network) you will have multiple LANs connected together using routers. I was taught many years ago that a WAN had nothing to do with the size of a computer network, but was simply connecting multiple LANs together across the public highway system, such as the internet.
People often try to explain concepts like LAN and WAN using terms and descriptions that have nothing to do with the definition. I often see people put numbers of computers into their definitions of LAN and WAN. If you have a three computer LAN than uses the public highway, as in the internet and internet addressing, to connect to another three computer network, the two LANs working together form a WAN.
What is the client server network model?
In the most common network model, client server, at least one centralized server manages shared resources and security for the other network users and computers. A network connection is only made when information needs to be accessed by a user. This lack of a continuous network connection provides network efficiency.
The client requests services or information from the server computer. The server responds to the client's request by sending the results of the request back to the client computer.
Security and permissions can be managed by administrators which cuts down on security and rights issues when dealing with a large number of workstations. This model allows for convenient backup services, reduces network traffic and provides a host of other services that come with the network operating system.
What are Peer-to-Peer Networks?
Simply sharing resources between computers, such as on a typical home network, every computer acts as both a client and a server. Any computer can share resources with another, and any computer can use the resources of another, given proper access rights.
This is a good solution when there are 10 or less users that are in close proximity to each other, but it is difficult to maintain security as the network grows. This model can be a security nightmare, because each workstation setting permissions for shared resources must be maintained at the workstation, and there is no centralized management. This model is only recommended in situations where security is not an issue.
Before microcomputers because cost effective dumb terminals were used to access very large main frame computes in remote locations. The local terminal was dumb in the sense that it was nothing more than a way for a keyboard and monitor to access another computer remotely with all the processing occurred on the remote computer. This model, sometimes referred to as a centralized model, is not very common.
The all encompassing footnote
A LAN could use something other than a TCP/IP addressing scheme, but the illustration of a LAN and WAN based network as I describe is a typical implementation
These definitions were written off of the top of my head based on many years of networking experience. Any resemblance to Wiki or any other website is merely coincidental. (Since I am defining basic terms I would hope that they are at least similar!)
I realize that I may have oversimplified some terms, but the goal here at Computerguru.net to deliver a basic understanding of the concepts in simple terms and not deliver a lecture on computer networking fundamentals to define each term. IMHO, I see many answers on various forums that over complicate matters as well as add quite a bit of stray information.