Comps of a network

Router

A router is a device that forwards data packets between computer networks, creating an overlay internetwork. A router is connected to two or more data lines from different networks. When a data packet comes in one of the lines, the router reads the address information in the packet to determine its ultimate destination. Then, using information in its routing table or routing policy, it directs the packet to the next network on its journey. Routers perform the "traffic directing" functions on the internet. A data packet is typically forwarded from one router to another through the networks that constitute the internetwork until it reaches its destination node.

Switch

A switch is a telecommunication device that receives a message from any device connected to it and then transmits the message only to the device for which the message was meant. This makes the switch a more intelligent device than a hub (which receives a message and then transmits it to all the other devices on its network). The network switch plays an integral part in most modern Ethernet Local area networks (LANs). Mid-to-large sized LANs contain a number of linked managed switches. Small office/ Home office (SOHO) applications typically use a single switch, or an all-purpose convergance device such as a residential gateway to access small office/home broadband services such as DSL or cable internet.

Hub

An Ethernet hub, active hub, network hub, repeater hub, multiport repeater or hub is a device for connecting multiple Ethernet devices together and making them act as a single network segment. It has multiple input/output (I/O) ports, in which a signal introduced at the input of any port appears at the output of every port except the original incoming. A hub works at the physical layer (layer 1) of the OSI model. The device is a form of multiport repeater. Repeater hubs also participate in collision detection, forwarding a jam signal to all ports if it detects a collision.

Server

A network server is a computer designed to process requests and deliver data to other (client) computers over a local network or the Internet. Network servers typically are configured with additional processing, memory and storage capacity to handle the load of servicing clients. Common types of network servers include:                                                                                    Web servers                                                                                                                                   Proxy servers                                                                                                                            FTPservers                                                                                                                                            Online game                                                                                                                      serversNumerous systems use this client / server networking model including Web sites and email services. An alternative model, peer-to-peer networking enables all computers to act as either a server or client as needed.

Client

A client is a computer program that, as part of its operation, relies on sending a request to another computer program (which may or may not be located on another computer). The term "client", however, may also be applied to computers or devices that run the client software or users that use the client software.For example, web browsers are clients that connect to web servers and retrieve web pages for display. Email clients retrieve email from mail servers. Online chat uses a variety of clients, which vary depending on the chat protocol being used. Multiplayer video games or online video games may run as a client on each computer.

NIC

The network interface controller implements the electronic circuitry required to communicate using a specific physical layer and data link layer standard such as Ethernet, Wi-Fi or Token Ring. This provides a base for a full network protocol stack, allowing communication among small groups of computers on the same LAN and large-scale network communications through routable protocols, such as IP.