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. See under packet switching. One of the key features of a packet is that it contains the destination address in addition to the data. In IP networks, packets are often called datagrams.

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) technologies connect a smaller number of devices that can be many kilometers apart.

An IP (Internet Protocol) Address is an alphanumeric label assigned to computers and other devices that connect to a network using an internet protocol. This address allows these devices to send and receive data over the internet. Every device that is capable of connecting to the internet has a unique IP address.

Bus Topology:  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 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.

 Network Token: In programming languages, a single element of a programming language. For example, a token could be a keyword, an operator, or a punctuation mark.

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: An agreed-upon format for transmitting data between two devices. The protocol determines the following:

Peer-Peer Architecture: 

Often referred to simply as peer-to-peer, or abbreviated P2P, a type of network in which each workstation has equivalent capabilities and responsibilities. This differs from client/server architectures, in which some computers are dedicated to serving the others. Peer-to-peer networks are generally simpler, but they usually do not offer the same performance under heavy loads.

Client/Server 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.