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

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. 

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 -- 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 Adress

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 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. 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.

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. In a ring network, each node takes a turn sending and receiving information through the use of a token

Network Token

In networking, 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. 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.

Tree Topology

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

Protocol

There are a variety of standard protocols from which programmer scan choose. Each has particular advantages and disadvantages; for example, some are simpler than others, some are more reliable, and some are faster.

peer-to-peer architecture

 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

 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 (file servers), printers (print servers), or network traffic (network servers ). 

Hubs

A hub is a common connection point for devices in a network. Hubs are commonly used to connect segments of a LAN. A hub contains multiple ports. When a packet arrives at one port, it is copied to the other ports so that all segments of the LAN can see all packets.