Computer Network

A computer network is a group of computers connected together in a way that allows information to be exchanged between the computers.

Packet

A piece of a message transmitted over a packet-switching network. One of the key features of a packet is that it contains the destination address in addition to the data.

Local Area Network (LAN)

A LAN is a network of computers that are in the same general physical location, usually within a building or a campus.

Wide Area Network (WAN)

 Wide area network (WAN) technologies connect a smaller number of devices that can be many kilometers apart.

Node

A node is anything that is connected to the network. While a node is typically a computer, it can also be something like a printer or CD-ROM tower.

Media Access Control (MAC)

This is the physical address of any device on the network. The MAC address, which is made up of two equal parts, is 6 bytes long. The first 3 bytes identify the company that made the NIC. The second 3 bytes are the serial number of the NIC itself.

IP Address

An IP address is an identifier for a computer or device on a TCP/IP network. Networks using the TCP/IP protocol route messages based on the IP address of the destination.

Bus Topology

Each node is daisy-chained along the same backbone. Information sent from a node travels along the backbone until it reaches its destination node.

Ring Topology

Rings have the nodes daisy-chained. The network comes back around to the first node, creating a complete circuit. In a ring network, each node takes a turn sending and receiving information through the use of a token. Only the node with the token is allowed to send data. All other nodes must wait for the token to come to them.

Network Token

A token is a special series of bits that travels around a token-ring network. As the token circulates, computers attached to the network can capture it. It enables its owner to send a message across the network. There is only one token for each network, so there is no possibility that two computers will attempt to transmit messages at the same time.

Star Topology

In a star network, each node is connected to a central device called a hub. The hub takes a signal that comes from any node and passes it along to all the other nodes in the network. A hub does not perform any type of filtering or routing of the data. It is simply a junction that joins all the different nodes together.

Tree Topology

A tree topology combines characteristics of linear bus and star topologies. It consists of groups of star-configured workstations connected to a linear bus backbone cable.

Protocol

It is an agreed-upon format for transmitting data between two devices. The protocol determines the type of error checking to be used, data compression method, how the sending device will indicate that it has finished sending a message, and how the receiving device will indicate that it has received a message.

Peer-Peer Architecture

It is a type of network in which each workstation has equivalent capabilities and responsibilities. Some computers are dedicated to serving the others. They usually do not offer the same performance under heavy loads.

Client/Server Architecture

Client-server architecture is a network architecture in which each computer or process on the network is either a client or a server. Servers are powerful computers or processes dedicated to managing disk drives, printers, or network traffic. Clients are PCs or workstations on which users run applications. Clients rely on servers for resources.