Computer Network

A 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)

Local Area Network (LAN) technologies connect many devices that are relatively close to each other, usually in the same building.

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.

An IP (Internet Protocol) Address is an alphanumeric label assigned to computers and other devices that connect to a network using an internet protocol.

IP Address

Each node is daisy-chained along the same backbone, similar to Christmas lights. Information sent from a node travels along the backbone until it reaches its destination node. Each end of a bus network must be terminated with a resistor to keep the signal that is sent by a node across the network from bouncing back when it reaches the end of the cable.

Bus Topology

Like a bus network, rings have the nodes daisy-chained. The difference is that the end of 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.

Ring Topology

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. The token acts like a ticket, enabling its owner to send a message across the network.

Network Token

In a star network, each node is connected to a central device called a hub.

Star 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.

Tree Topology

An agreed-upon format for transmitting data between two devices.

Protocol

A type of network in which each workstation has equivalent capabilities and responsibilities. Peer-to-peer networks are generally simpler, but they usually do not offer the same performance under heavy loads.

Peer-To-Peer Architecture

Client-server architecture (client/server) is a network architecture in which each computer or process on the network is either a client or a server.

Client/Server Architecture