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Classified in Computers

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Introducing networks

A network is created when more than one device is connected together. A network can be a small collection of computers connected within a building (eg a school, business or home) or it can be a wide collection of computers connected around the world.

Advantages

-Communication – it is easy (and often free) to communicate using email, text messages, voice calls and video calls.

-Roaming – if information is stored on a network, it means users are not fixed to one place. They can use computers anywhere in the world to access their information.

-Sharing information – it is easy to share files and information over a network. Music and video files, for instance, can be stored on one device and shared across many computers, so every computer does not need to fill the hard drive with files.

-Sharing resources – it is easy to share resources such as printers. Twenty computers in a room could share one printer over a network.

-Sharing software – it is possible to stream software using web applications. This avoids needing to download and store the whole software file.

Disadvantages

-Dependence – users relying on a network might be stuck without access to it.

-Hacking - criminal hackers attempt to break into networks in order to steal personal information and banking details. This wouldn't be possible on a stand-alone computer without physically getting into the room, but with a network it is easier to gain access.

-Hardware – routers, network cards and other network hardware is required to set up a network. At home, it is quite easy to set up a wireless network without much technical expertise. However, a complicated network in a school or an office would require professional expertise.

-Viruses - networks make it easier to share viruses and other malware. They can quickly spread and damage files on many computers via a network.

LAN:A LAN (local area network) is A network of computers within the same building, such as a school, home or Business. A LAN is not necessarily connected to the internet.

WAN:A WAN (wide area network) is Created when LANs are connected. This requires media such as broadband cables, And can connect up organizations based in different geographical places. The Internet is a WAN.

VPN: A VPN (virtual private Network) is usually hosted securely on another network, such as the internet, To provide connectivity. VPNs are often used when working on secure information Held by a company or school.

WPAN: A WPAN (wireless personal area Network) allows an individual to connect devices (such as a Smartphone) to a Desktop machine, or to form a Bluetooth connection with devices in a car. A Wired personal network is called a PAN (personal area network).

Routers: A router can form a LAN by Connecting devices within a building. It also makes it possible to connect Different networks together. Homes and businesses use a router to connect to The internet. A router can often incorporate a modem within the hardware.

Modems: A modem enables a computer to Connect to the internet over a telephone line. A modem converts digital signals From a computer to analogue signals that are then sent down the telephone line. A modem on the other end converts the analogue signal back to a digital signal Which another computer can understand.

Switches: A switch Performs a similar role to a hub and a bridge but is more powerful. It stores The MAC addresses of devices on a network and filters data packets to see which Devices have asked for them. This makes a switch more efficient when demand is High. If, for example, a game involved lots of data being passed between Machines, then a switch could reduce the amount of latency.

Hubs: A hub broadcasts data to all Devices on a network. This can use a lot of bandwidth as it results in Unnecessary data being sent - not all computers might need to receive the data. A hub would be useful to link up a few games consoles for a local multiplayer Game using a wired LAN.

Bridges: A bridge is used to connect Two separate LAN networks. A computer can act as a bridge through the operating System. A bridge looks for the receiving device before it sends the message. This means that it will not send a message if the receiving computer is not There. It will check to see if the receiver has already had the message. This Can help save unnecessary data transfers, which improves the performance of a Network.


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