WHAT IS A COMPUTER NETWORK?
A computer network is any two, or more computers connected together(wired or wireless) that are able to communicate electronically and share resources.
COMPONENTS OF A COMPUTER NETWORK.
A computer network is composed of several components that work together to create the network.
Network Interface Card(NIC)
It is a computers hardware component that contains the computer’s hardware address referred to as the MAC address(Media Access Control Address). It uniquely identifies a device in a network.
There are two types of NIC’s:
wireless — Uses radio wave technology to connect to a network. it is the technology used by most of the present day
laptops, smartphones etc.
wired — Mainly used by a computer when the connection to a network is via a cable.
Switches.
A switch is a physical networking device that takes network packets being sent by network devices connected to its physical ports and sends them out through ports that lead to their intended destinations only.
Hub.
Unlike a switch, a hub takes in network packets being sent by network devices attached to it’s physical ports but instead of sending the packets out through a port leading to the intended destination, it sends out the packet to all the interconnected devices.
Router.
A router offers forwarding and routing of network traffic specifically at layer 3(the network layer). A router basically interconnects different networks. The following is an example of a path taken by a packet.
Device(Your laptop) —>hub|switch–>router–>Internet.
Network Cables.
Is a transmission media that inter-connects devices in a network.
coaxial cable – Is a shielded copper cable that is designed to significantly reduce electrical Noise. Provides a speed aof up to 10 mbps for ranges of up to 500 meters. They mainly use the BNC connector(Neil-Concelman(BNC) connector.
Fiber optic cables – Transmits data using light beams. it supports a range of standards of 10mbps, 100mbps, 1gbps and 10gbps. It is very expensive compared to other transmission media.
Serial cables.- Supports the transmission of data as a serial stream of bits. Serial operates in layer 1(Physical layer). They are still in use in areas such as console management in HP.
Ethernet – It supports a 4 copper wire pair contained within a sheath which may or may not be shielded against external electrical interface. Transmission capacity varies with the category of the cable, category 5 ethernet supports speed of up to 100mbps, while category 5 extended(cat5e) supports Gigabyte transmission and higher. Category 6 supports speeds of upto 100gbs.
Modem
It is used to connect a computer to the internet using a telephone line. Various internet service provides(telephone) offer their uniquely designed modems that can be purchased and used to access the internet via their network.
Bridge.
A bridge is a network device that interconnects LANs(Local Area Networks) that use a similar protocol. Bridges increase the coverage of a single LAN.
