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.

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) - If the computers are far apart (such as across town or in different cities), then a Wide Area Network (WAN) is typically used.

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) address - This is the physical address of any device -- such as the NIC in a computer -- 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 is short for Internet Protocol (IP) address. An IP address is an identifier for a computer or device on a TCP/IP network. 

Bus - Each node is daisy-chained (connected one right after the other) along the same backbone, similar to Christmas lights. Information sent from a node travels along the backbone until it reaches its destination node.

Ring - 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. 

Star - 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 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.

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 determines the following:

the type of error checking to be used

data compression method, if any

how the sending device will indicate that it has finished sending a message

how the receiving device will indicate that it has received a message

peer-to-peer - a type of network in which each workstation has equivalent capabilities and responsibilities. 

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.