Computer Network

A group of computers connected in a way so that information can be exchanged between computers.

Packet

Piece of message that is transmitted over a packet-switching network. One key feature of packet is that it has the destination address plus data and in IP networks, packets are called datagrams.

Local Area Network (LAN)

A network of devices or computers that are in the same physical location, usually a building.

Wide Area Network (WAN)

Computers or devices that are far apart from each other. Typically kilometers apart and across towns or in different cities.

Node

Anything that is connected to the network. Examples are computer, printer, CD-ROM tower, etc.

Media Access Control (MAC)

Physical address of any device like Network Interface Card or NIC in a computer on a network. It is made up of 2 equal parts and is 6 bytes long. The first 3 bytes identifies the company that made the NIC and the second 3 bytes are the serial number of NIC.

IP Address

The combine set of all letters in the alphabet and numbers from 0 to 9 label assigned to computers and devices that connect to a network using internet protocol. The types are public IP address, private IP address, and static and dynamic IP address.

Bus Topology

The nodes are connected one right after the other along the same backbone and information sent from a node travels along with the backbone until it reaches its destination. Each end of a bus network be ended with a resistor to keep the signal that is sent from a node across the network from bouncing back when it reaches the end of the cable.

Ring Topology 

Devices are connected to one another in a closed loop so each device is directly connected to two other devices. They are expensive and difficult to install but they offer high bandwidth and can span long distances.

Network Token

Special series of bits that travels around a token-ring network and as it circulates, computers attached to the network can capture it. It acts like a ticket, enabling its owner to send a message across the network and there is only one token for each network.

Star Topology

Devices are connected to a central hub and they are relatively easy to install and manage but bottlenecks can happen since all data data must pass through the hub.

Tree Topology

Combines characteristics of linear bus and star topologies and consists of groups of star-configured workstations connected to linear bus backbone cable.

Protocol

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

Peer-Peer Architecture

Type of network that each workstation has equivalent capabilities and responsibilities. Types are pure P2P network, unstructured P2P network, structured P2P network, and hybrid P2P network.

Client/Server Architecture

A network architecture in which each computer or process on the network is either a client or server.